diff --git a/compiler/rustc_ast_lowering/src/index.rs b/compiler/rustc_ast_lowering/src/index.rs
index 62935a2b1f718..5eab21bf79a90 100644
--- a/compiler/rustc_ast_lowering/src/index.rs
+++ b/compiler/rustc_ast_lowering/src/index.rs
@@ -52,7 +52,9 @@ pub(super) fn index_hir<'hir>(
     };
 
     match item {
-        OwnerNode::Crate(citem) => collector.visit_mod(&citem, citem.inner, hir::CRATE_HIR_ID),
+        OwnerNode::Crate(citem) => {
+            collector.visit_mod(&citem, citem.spans.inner_span, hir::CRATE_HIR_ID)
+        }
         OwnerNode::Item(item) => collector.visit_item(item),
         OwnerNode::TraitItem(item) => collector.visit_trait_item(item),
         OwnerNode::ImplItem(item) => collector.visit_impl_item(item),
diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index c8fd96309a6cd..a8bd8c92a41c4 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -124,7 +124,7 @@ impl<'a, 'hir> ItemLowerer<'a, 'hir> {
         debug_assert_eq!(self.resolver.local_def_id(CRATE_NODE_ID), CRATE_DEF_ID);
 
         self.with_lctx(CRATE_NODE_ID, |lctx| {
-            let module = lctx.lower_mod(&c.items, c.spans.inner_span);
+            let module = lctx.lower_mod(&c.items, &c.spans);
             lctx.lower_attrs(hir::CRATE_HIR_ID, &c.attrs);
             hir::OwnerNode::Crate(lctx.arena.alloc(module))
         })
@@ -186,9 +186,12 @@ impl<'a, 'hir> ItemLowerer<'a, 'hir> {
 }
 
 impl<'hir> LoweringContext<'_, 'hir> {
-    pub(super) fn lower_mod(&mut self, items: &[P<Item>], inner: Span) -> hir::Mod<'hir> {
+    pub(super) fn lower_mod(&mut self, items: &[P<Item>], spans: &ModSpans) -> hir::Mod<'hir> {
         hir::Mod {
-            inner: self.lower_span(inner),
+            spans: hir::ModSpans {
+                inner_span: self.lower_span(spans.inner_span),
+                inject_use_span: self.lower_span(spans.inject_use_span),
+            },
             item_ids: self.arena.alloc_from_iter(items.iter().flat_map(|x| self.lower_item_ref(x))),
         }
     }
@@ -308,8 +311,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 })
             }
             ItemKind::Mod(_, ref mod_kind) => match mod_kind {
-                ModKind::Loaded(items, _, ModSpans { inner_span, inject_use_span: _ }) => {
-                    hir::ItemKind::Mod(self.lower_mod(items, *inner_span))
+                ModKind::Loaded(items, _, spans) => {
+                    hir::ItemKind::Mod(self.lower_mod(items, spans))
                 }
                 ModKind::Unloaded => panic!("`mod` items should have been loaded by now"),
             },
diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index ca83941f600ca..2c5260616c7da 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -46,18 +46,7 @@ pub fn expand_deriving_default(
                     StaticStruct(_, fields) => {
                         default_struct_substructure(cx, trait_span, substr, fields)
                     }
-                    StaticEnum(enum_def, _) => {
-                        if !cx.sess.features_untracked().derive_default_enum {
-                            rustc_session::parse::feature_err(
-                                cx.parse_sess(),
-                                sym::derive_default_enum,
-                                span,
-                                "deriving `Default` on enums is experimental",
-                            )
-                            .emit();
-                        }
-                        default_enum_substructure(cx, trait_span, enum_def)
-                    }
+                    StaticEnum(enum_def, _) => default_enum_substructure(cx, trait_span, enum_def),
                     _ => cx.span_bug(trait_span, "method in `derive(Default)`"),
                 }
             })),
diff --git a/compiler/rustc_const_eval/src/interpret/step.rs b/compiler/rustc_const_eval/src/interpret/step.rs
index eb1a184bf9b21..e6dfdf54a32d1 100644
--- a/compiler/rustc_const_eval/src/interpret/step.rs
+++ b/compiler/rustc_const_eval/src/interpret/step.rs
@@ -196,27 +196,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 self.write_immediate(*val, &dest)?;
             }
 
-            Aggregate(ref kind, ref operands) => {
-                // active_field_index is for union initialization.
-                let (dest, active_field_index) = match **kind {
-                    mir::AggregateKind::Adt(adt_did, variant_index, _, _, active_field_index) => {
-                        self.write_discriminant(variant_index, &dest)?;
-                        if self.tcx.adt_def(adt_did).is_enum() {
-                            assert!(active_field_index.is_none());
-                            (self.place_downcast(&dest, variant_index)?, None)
-                        } else {
-                            if active_field_index.is_some() {
-                                assert_eq!(operands.len(), 1);
-                            }
-                            (dest, active_field_index)
-                        }
-                    }
-                    _ => (dest, None),
-                };
+            Aggregate(box ref kind, ref operands) => {
+                assert!(matches!(kind, mir::AggregateKind::Array(..)));
 
-                for (i, operand) in operands.iter().enumerate() {
+                for (field_index, operand) in operands.iter().enumerate() {
                     let op = self.eval_operand(operand, None)?;
-                    let field_index = active_field_index.unwrap_or(i);
                     let field_dest = self.place_field(&dest, field_index)?;
                     self.copy_op(&op, &field_dest)?;
                 }
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs
index 01af95851357e..79d427ccc4469 100644
--- a/compiler/rustc_const_eval/src/transform/validate.rs
+++ b/compiler/rustc_const_eval/src/transform/validate.rs
@@ -315,9 +315,8 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                                     | ty::FnPtr(..)
                             )
                         }
-                        // None of the possible types have lifetimes, so we can just compare
-                        // directly
-                        if a != b {
+                        // The function pointer types can have lifetimes
+                        if !self.mir_assign_valid_types(a, b) {
                             self.fail(
                                 location,
                                 format!("Cannot compare unequal types {:?} and {:?}", a, b),
@@ -464,7 +463,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 };
                 // since CopyNonOverlapping is parametrized by 1 type,
                 // we only need to check that they are equal and not keep an extra parameter.
-                if op_src_ty != op_dst_ty {
+                if !self.mir_assign_valid_types(op_src_ty, op_dst_ty) {
                     self.fail(location, format!("bad arg ({:?} != {:?})", op_src_ty, op_dst_ty));
                 }
 
diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs
index e37251c9c2439..048039343a7a2 100644
--- a/compiler/rustc_feature/src/accepted.rs
+++ b/compiler/rustc_feature/src/accepted.rs
@@ -126,6 +126,8 @@ declare_features! (
     (accepted, default_type_params, "1.0.0", None, None),
     /// Allows `#[deprecated]` attribute.
     (accepted, deprecated, "1.9.0", Some(29935), None),
+    /// Allows `#[derive(Default)]` and `#[default]` on enums.
+    (accepted, derive_default_enum, "1.62.0", Some(86985), None),
     /// Allows the use of destructuring assignments.
     (accepted, destructuring_assignment, "1.59.0", Some(71126), None),
     /// Allows `#[doc(alias = "...")]`.
diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs
index 8340a0b360ef7..f3d4c8ab43843 100644
--- a/compiler/rustc_feature/src/active.rs
+++ b/compiler/rustc_feature/src/active.rs
@@ -368,8 +368,6 @@ declare_features! (
     (active, deprecated_safe, "1.61.0", Some(94978), None),
     /// Allows having using `suggestion` in the `#[deprecated]` attribute.
     (active, deprecated_suggestion, "1.61.0", Some(94785), None),
-    /// Allows `#[derive(Default)]` and `#[default]` on enums.
-    (active, derive_default_enum, "1.56.0", Some(86985), None),
     /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
     (active, doc_auto_cfg, "1.58.0", Some(43781), None),
     /// Allows `#[doc(cfg(...))]`.
diff --git a/compiler/rustc_feature/src/lib.rs b/compiler/rustc_feature/src/lib.rs
index bfc537cfae2cb..940c4ecdcc23a 100644
--- a/compiler/rustc_feature/src/lib.rs
+++ b/compiler/rustc_feature/src/lib.rs
@@ -11,7 +11,7 @@
 //! even if it is stabilized or removed, *do not remove it*. Instead, move the
 //! symbol to the `accepted` or `removed` modules respectively.
 
-#![feature(derive_default_enum)]
+#![cfg_attr(bootstrap, feature(derive_default_enum))]
 #![feature(once_cell)]
 
 mod accepted;
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index ff8b13d31122e..68ae2441af797 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -2557,11 +2557,17 @@ impl FnRetTy<'_> {
 
 #[derive(Encodable, Debug, HashStable_Generic)]
 pub struct Mod<'hir> {
+    pub spans: ModSpans,
+    pub item_ids: &'hir [ItemId],
+}
+
+#[derive(Copy, Clone, Debug, HashStable_Generic, Encodable)]
+pub struct ModSpans {
     /// A span from the first token past `{` to the last token until `}`.
     /// For `mod foo;`, the inner span ranges from the first token
     /// to the last token in the external file.
-    pub inner: Span,
-    pub item_ids: &'hir [ItemId],
+    pub inner_span: Span,
+    pub inject_use_span: Span,
 }
 
 #[derive(Debug, HashStable_Generic)]
@@ -3059,8 +3065,8 @@ impl<'hir> OwnerNode<'hir> {
             OwnerNode::Item(Item { span, .. })
             | OwnerNode::ForeignItem(ForeignItem { span, .. })
             | OwnerNode::ImplItem(ImplItem { span, .. })
-            | OwnerNode::TraitItem(TraitItem { span, .. })
-            | OwnerNode::Crate(Mod { inner: span, .. }) => *span,
+            | OwnerNode::TraitItem(TraitItem { span, .. }) => *span,
+            OwnerNode::Crate(Mod { spans: ModSpans { inner_span, .. }, .. }) => *inner_span,
         }
     }
 
diff --git a/compiler/rustc_infer/src/lib.rs b/compiler/rustc_infer/src/lib.rs
index 08e005364ce64..e859bcaec1206 100644
--- a/compiler/rustc_infer/src/lib.rs
+++ b/compiler/rustc_infer/src/lib.rs
@@ -17,7 +17,7 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
-#![feature(derive_default_enum)]
+#![cfg_attr(bootstrap, feature(derive_default_enum))]
 #![feature(extend_one)]
 #![feature(label_break_value)]
 #![feature(let_chains)]
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 65796fbc698d8..08cd40f38efce 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -584,7 +584,7 @@ impl<'hir> Map<'hir> {
             Some(OwnerNode::Item(&Item { span, kind: ItemKind::Mod(ref m), .. })) => {
                 (m, span, hir_id)
             }
-            Some(OwnerNode::Crate(item)) => (item, item.inner, hir_id),
+            Some(OwnerNode::Crate(item)) => (item, item.spans.inner_span, hir_id),
             node => panic!("not a module: {:?}", node),
         }
     }
@@ -1012,7 +1012,7 @@ impl<'hir> Map<'hir> {
             Node::Infer(i) => i.span,
             Node::Visibility(v) => bug!("unexpected Visibility {:?}", v),
             Node::Local(local) => local.span,
-            Node::Crate(item) => item.inner,
+            Node::Crate(item) => item.spans.inner_span,
         };
         Some(span)
     }
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index fd2b5f5335f69..199b5fa0314b3 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -30,7 +30,7 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(core_intrinsics)]
-#![feature(derive_default_enum)]
+#![cfg_attr(bootstrap, feature(derive_default_enum))]
 #![feature(discriminant_kind)]
 #![feature(exhaustive_patterns)]
 #![feature(get_mut_unchecked)]
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index db7e973fb6223..49769b7ae3d89 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -2518,7 +2518,8 @@ pub enum Rvalue<'tcx> {
     /// * `Offset` has the same semantics as [`offset`](pointer::offset), except that the second
     ///   parameter may be a `usize` as well.
     /// * The comparison operations accept `bool`s, `char`s, signed or unsigned integers, floats,
-    ///   raw pointers, or function pointers of matching types and return a `bool`.
+    ///   raw pointers, or function pointers and return a `bool`. The types of the operands must be
+    ///   matching, up to the usual caveat of the lifetimes in function pointers.
     /// * Left and right shift operations accept signed or unsigned integers not necessarily of the
     ///   same type and return a value of the same type as their LHS. Like in Rust, the RHS is
     ///   truncated as needed.
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index 5ab412dc777de..e5ee1d5dab92e 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -182,16 +182,7 @@ impl<'a> StringReader<'a> {
             }
             rustc_lexer::TokenKind::BlockComment { doc_style, terminated } => {
                 if !terminated {
-                    let msg = match doc_style {
-                        Some(_) => "unterminated block doc-comment",
-                        None => "unterminated block comment",
-                    };
-                    let last_bpos = self.pos;
-                    self.sess.span_diagnostic.span_fatal_with_code(
-                        self.mk_sp(start, last_bpos),
-                        msg,
-                        error_code!(E0758),
-                    );
+                    self.report_unterminated_block_comment(start, doc_style);
                 }
 
                 // Skip non-doc comments
@@ -553,6 +544,55 @@ impl<'a> StringReader<'a> {
         err.emit()
     }
 
+    fn report_unterminated_block_comment(&self, start: BytePos, doc_style: Option<DocStyle>) {
+        let msg = match doc_style {
+            Some(_) => "unterminated block doc-comment",
+            None => "unterminated block comment",
+        };
+        let last_bpos = self.pos;
+        let mut err = self.sess.span_diagnostic.struct_span_fatal_with_code(
+            self.mk_sp(start, last_bpos),
+            msg,
+            error_code!(E0758),
+        );
+        let mut nested_block_comment_open_idxs = vec![];
+        let mut last_nested_block_comment_idxs = None;
+        let mut content_chars = self.str_from(start).char_indices().peekable();
+
+        while let Some((idx, current_char)) = content_chars.next() {
+            match content_chars.peek() {
+                Some((_, '*')) if current_char == '/' => {
+                    nested_block_comment_open_idxs.push(idx);
+                }
+                Some((_, '/')) if current_char == '*' => {
+                    last_nested_block_comment_idxs =
+                        nested_block_comment_open_idxs.pop().map(|open_idx| (open_idx, idx));
+                }
+                _ => {}
+            };
+        }
+
+        if let Some((nested_open_idx, nested_close_idx)) = last_nested_block_comment_idxs {
+            err.span_label(self.mk_sp(start, start + BytePos(2)), msg)
+                .span_label(
+                    self.mk_sp(
+                        start + BytePos(nested_open_idx as u32),
+                        start + BytePos(nested_open_idx as u32 + 2),
+                    ),
+                    "...as last nested comment starts here, maybe you want to close this instead?",
+                )
+                .span_label(
+                    self.mk_sp(
+                        start + BytePos(nested_close_idx as u32),
+                        start + BytePos(nested_close_idx as u32 + 2),
+                    ),
+                    "...and last nested comment terminates here.",
+                );
+        }
+
+        err.emit();
+    }
+
     // RFC 3101 introduced the idea of (reserved) prefixes. As of Rust 2021,
     // using a (unknown) prefix is an error. In earlier editions, however, they
     // only result in a (allowed by default) lint, and are treated as regular
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index c45326e1e6e6c..a9444972130a8 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -80,6 +80,7 @@ impl CheckAttrVisitor<'_> {
                     self.check_rustc_must_implement_one_of(attr, span, target)
                 }
                 sym::target_feature => self.check_target_feature(hir_id, attr, span, target),
+                sym::thread_local => self.check_thread_local(attr, span, target),
                 sym::track_caller => {
                     self.check_track_caller(hir_id, attr.span, attrs, span, target)
                 }
@@ -523,6 +524,21 @@ impl CheckAttrVisitor<'_> {
         }
     }
 
+    /// Checks if the `#[thread_local]` attribute on `item` is valid. Returns `true` if valid.
+    fn check_thread_local(&self, attr: &Attribute, span: Span, target: Target) -> bool {
+        match target {
+            Target::ForeignStatic | Target::Static => true,
+            _ => {
+                self.tcx
+                    .sess
+                    .struct_span_err(attr.span, "attribute should be applied to a static")
+                    .span_label(span, "not a static")
+                    .emit();
+                false
+            }
+        }
+    }
+
     fn doc_attr_str_error(&self, meta: &NestedMetaItem, attr_name: &str) {
         self.tcx
             .sess
diff --git a/compiler/rustc_save_analysis/src/dump_visitor.rs b/compiler/rustc_save_analysis/src/dump_visitor.rs
index 1eb575e0db2a6..22d0a20395ec7 100644
--- a/compiler/rustc_save_analysis/src/dump_visitor.rs
+++ b/compiler/rustc_save_analysis/src/dump_visitor.rs
@@ -1095,11 +1095,11 @@ impl<'tcx> DumpVisitor<'tcx> {
 
         let sm = self.tcx.sess.source_map();
         let krate_mod = self.tcx.hir().root_module();
-        let filename = sm.span_to_filename(krate_mod.inner);
+        let filename = sm.span_to_filename(krate_mod.spans.inner_span);
         let data_id = id_from_hir_id(id, &self.save_ctxt);
         let children =
             krate_mod.item_ids.iter().map(|i| id_from_def_id(i.def_id.to_def_id())).collect();
-        let span = self.span_from_span(krate_mod.inner);
+        let span = self.span_from_span(krate_mod.spans.inner_span);
         let attrs = self.tcx.hir().attrs(id);
 
         self.dumper.dump_def(
diff --git a/compiler/rustc_save_analysis/src/lib.rs b/compiler/rustc_save_analysis/src/lib.rs
index 08a990c65fff7..102268c6ca352 100644
--- a/compiler/rustc_save_analysis/src/lib.rs
+++ b/compiler/rustc_save_analysis/src/lib.rs
@@ -282,7 +282,7 @@ impl<'tcx> SaveContext<'tcx> {
                 let qualname = format!("::{}", self.tcx.def_path_str(def_id));
 
                 let sm = self.tcx.sess.source_map();
-                let filename = sm.span_to_filename(m.inner);
+                let filename = sm.span_to_filename(m.spans.inner_span);
 
                 filter!(self.span_utils, item.ident.span);
 
diff --git a/compiler/rustc_session/src/lib.rs b/compiler/rustc_session/src/lib.rs
index 3151b025ffff7..054b18b6b633a 100644
--- a/compiler/rustc_session/src/lib.rs
+++ b/compiler/rustc_session/src/lib.rs
@@ -1,7 +1,7 @@
 #![feature(crate_visibility_modifier)]
-#![feature(derive_default_enum)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
+#![cfg_attr(bootstrap, feature(derive_default_enum))]
 #![feature(let_else)]
 #![feature(min_specialization)]
 #![feature(never_type)]
diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs
index 7523b8441013a..2ae7f34a91e00 100644
--- a/compiler/rustc_trait_selection/src/lib.rs
+++ b/compiler/rustc_trait_selection/src/lib.rs
@@ -16,7 +16,7 @@
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(crate_visibility_modifier)]
-#![feature(derive_default_enum)]
+#![cfg_attr(bootstrap, feature(derive_default_enum))]
 #![feature(drain_filter)]
 #![feature(hash_drain_filter)]
 #![feature(label_break_value)]
diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs
index e6560ca4d9b90..2921176ca4b38 100644
--- a/compiler/rustc_typeck/src/check/method/suggest.rs
+++ b/compiler/rustc_typeck/src/check/method/suggest.rs
@@ -8,7 +8,7 @@ use rustc_errors::{
     MultiSpan,
 };
 use rustc_hir as hir;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{ExprKind, Node, QPath};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
@@ -1473,12 +1473,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    fn suggest_use_candidates(
-        &self,
-        err: &mut Diagnostic,
-        mut msg: String,
-        candidates: Vec<DefId>,
-    ) {
+    fn suggest_use_candidates(&self, err: &mut Diagnostic, msg: String, candidates: Vec<DefId>) {
         let parent_map = self.tcx.visible_parent_map(());
 
         // Separate out candidates that must be imported with a glob, because they are named `_`
@@ -1502,80 +1497,28 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         });
 
         let module_did = self.tcx.parent_module(self.body_id);
-        let (span, found_use) = find_use_placement(self.tcx, module_did);
-        if let Some(span) = span {
-            let path_strings = candidates.iter().map(|trait_did| {
-                // Produce an additional newline to separate the new use statement
-                // from the directly following item.
-                let additional_newline = if found_use { "" } else { "\n" };
-                format!(
-                    "use {};\n{}",
-                    with_crate_prefix!(self.tcx.def_path_str(*trait_did)),
-                    additional_newline
-                )
-            });
+        let (module, _, _) = self.tcx.hir().get_module(module_did);
+        let span = module.spans.inject_use_span;
 
-            let glob_path_strings = globs.iter().map(|trait_did| {
-                let parent_did = parent_map.get(trait_did).unwrap();
+        let path_strings = candidates.iter().map(|trait_did| {
+            format!("use {};\n", with_crate_prefix!(self.tcx.def_path_str(*trait_did)),)
+        });
 
-                // Produce an additional newline to separate the new use statement
-                // from the directly following item.
-                let additional_newline = if found_use { "" } else { "\n" };
-                format!(
-                    "use {}::*; // trait {}\n{}",
-                    with_crate_prefix!(self.tcx.def_path_str(*parent_did)),
-                    self.tcx.item_name(*trait_did),
-                    additional_newline
-                )
-            });
+        let glob_path_strings = globs.iter().map(|trait_did| {
+            let parent_did = parent_map.get(trait_did).unwrap();
+            format!(
+                "use {}::*; // trait {}\n",
+                with_crate_prefix!(self.tcx.def_path_str(*parent_did)),
+                self.tcx.item_name(*trait_did),
+            )
+        });
 
-            err.span_suggestions(
-                span,
-                &msg,
-                path_strings.chain(glob_path_strings),
-                Applicability::MaybeIncorrect,
-            );
-        } else {
-            let limit = if candidates.len() + globs.len() == 5 { 5 } else { 4 };
-            for (i, trait_did) in candidates.iter().take(limit).enumerate() {
-                if candidates.len() + globs.len() > 1 {
-                    msg.push_str(&format!(
-                        "\ncandidate #{}: `use {};`",
-                        i + 1,
-                        with_crate_prefix!(self.tcx.def_path_str(*trait_did))
-                    ));
-                } else {
-                    msg.push_str(&format!(
-                        "\n`use {};`",
-                        with_crate_prefix!(self.tcx.def_path_str(*trait_did))
-                    ));
-                }
-            }
-            for (i, trait_did) in
-                globs.iter().take(limit.saturating_sub(candidates.len())).enumerate()
-            {
-                let parent_did = parent_map.get(trait_did).unwrap();
-
-                if candidates.len() + globs.len() > 1 {
-                    msg.push_str(&format!(
-                        "\ncandidate #{}: `use {}::*; // trait {}`",
-                        candidates.len() + i + 1,
-                        with_crate_prefix!(self.tcx.def_path_str(*parent_did)),
-                        self.tcx.item_name(*trait_did),
-                    ));
-                } else {
-                    msg.push_str(&format!(
-                        "\n`use {}::*; // trait {}`",
-                        with_crate_prefix!(self.tcx.def_path_str(*parent_did)),
-                        self.tcx.item_name(*trait_did),
-                    ));
-                }
-            }
-            if candidates.len() > limit {
-                msg.push_str(&format!("\nand {} others", candidates.len() + globs.len() - limit));
-            }
-            err.note(&msg);
-        }
+        err.span_suggestions(
+            span,
+            &msg,
+            path_strings.chain(glob_path_strings),
+            Applicability::MaybeIncorrect,
+        );
     }
 
     fn suggest_valid_traits(
@@ -2106,53 +2049,6 @@ pub fn all_traits(tcx: TyCtxt<'_>) -> Vec<TraitInfo> {
     tcx.all_traits().map(|def_id| TraitInfo { def_id }).collect()
 }
 
-fn find_use_placement<'tcx>(tcx: TyCtxt<'tcx>, target_module: LocalDefId) -> (Option<Span>, bool) {
-    // FIXME(#94854): this code uses an out-of-date method for inferring a span
-    // to suggest. It would be better to thread the ModSpans from the AST into
-    // the HIR, and then use that to drive the suggestion here.
-
-    let mut span = None;
-    let mut found_use = false;
-    let (module, _, _) = tcx.hir().get_module(target_module);
-
-    // Find a `use` statement.
-    for &item_id in module.item_ids {
-        let item = tcx.hir().item(item_id);
-        match item.kind {
-            hir::ItemKind::Use(..) => {
-                // Don't suggest placing a `use` before the prelude
-                // import or other generated ones.
-                if !item.span.from_expansion() {
-                    span = Some(item.span.shrink_to_lo());
-                    found_use = true;
-                    break;
-                }
-            }
-            // Don't place `use` before `extern crate`...
-            hir::ItemKind::ExternCrate(_) => {}
-            // ...but do place them before the first other item.
-            _ => {
-                if span.map_or(true, |span| item.span < span) {
-                    if !item.span.from_expansion() {
-                        span = Some(item.span.shrink_to_lo());
-                        // Don't insert between attributes and an item.
-                        let attrs = tcx.hir().attrs(item.hir_id());
-                        // Find the first attribute on the item.
-                        // FIXME: This is broken for active attributes.
-                        for attr in attrs {
-                            if !attr.span.is_dummy() && span.map_or(true, |span| attr.span < span) {
-                                span = Some(attr.span.shrink_to_lo());
-                            }
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    (span, found_use)
-}
-
 fn print_disambiguation_help<'tcx>(
     item_name: Ident,
     args: Option<&'tcx [hir::Expr<'tcx>]>,
diff --git a/library/core/src/default.rs b/library/core/src/default.rs
index fb862f7df947b..1ce00828bf344 100644
--- a/library/core/src/default.rs
+++ b/library/core/src/default.rs
@@ -52,6 +52,23 @@
 /// This trait can be used with `#[derive]` if all of the type's fields implement
 /// `Default`. When `derive`d, it will use the default value for each field's type.
 ///
+/// ### `enum`s
+///
+/// When using `#[derive(Default)]` on an `enum`, you need to choose which unit variant will be
+/// default. You do this by placing the `#[default]` attribute on the variant.
+///
+/// ```
+/// #[derive(Default)]
+/// enum Kind {
+///     #[default]
+///     A,
+///     B,
+///     C,
+/// }
+/// ```
+///
+/// You cannot use the `#[default]` attribute on non-unit or non-exhaustive variants.
+///
 /// ## How can I implement `Default`?
 ///
 /// Provide an implementation for the `default()` method that returns the value of
diff --git a/library/core/src/iter/traits/iterator.rs b/library/core/src/iter/traits/iterator.rs
index 53fbe4cbc42f5..69f06fb06ef5d 100644
--- a/library/core/src/iter/traits/iterator.rs
+++ b/library/core/src/iter/traits/iterator.rs
@@ -470,6 +470,10 @@ pub trait Iterator {
     /// it will first try to advance the first iterator at most one time and if it still yielded an item
     /// try to advance the second iterator at most one time.
     ///
+    /// To 'undo' the result of zipping up two iterators, see [`unzip`].
+    ///
+    /// [`unzip`]: Iterator::unzip
+    ///
     /// # Examples
     ///
     /// Basic usage:
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 6546a5244fd03..2b613a71bc13b 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -167,7 +167,7 @@
 #![feature(const_precise_live_drops)]
 #![feature(const_refs_to_cell)]
 #![feature(decl_macro)]
-#![feature(derive_default_enum)]
+#![cfg_attr(bootstrap, feature(derive_default_enum))]
 #![feature(deprecated_suggestion)]
 #![feature(doc_cfg)]
 #![feature(doc_notable_trait)]
diff --git a/library/std/src/sys/unix/futex.rs b/library/std/src/sys/unix/futex.rs
index b45d1c0149cb4..62760373a6aff 100644
--- a/library/std/src/sys/unix/futex.rs
+++ b/library/std/src/sys/unix/futex.rs
@@ -4,7 +4,7 @@
     all(target_os = "emscripten", target_feature = "atomics")
 ))]
 
-use crate::sync::atomic::AtomicI32;
+use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
 /// Wait for a futex_wake operation to wake us.
@@ -13,7 +13,7 @@ use crate::time::Duration;
 ///
 /// Returns false on timeout, and true in all other cases.
 #[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option<Duration>) -> bool {
+pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) -> bool {
     use super::time::Timespec;
     use crate::ptr::null;
     use crate::sync::atomic::Ordering::Relaxed;
@@ -35,7 +35,7 @@ pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option<Duration>) -
         let r = unsafe {
             libc::syscall(
                 libc::SYS_futex,
-                futex as *const AtomicI32,
+                futex as *const AtomicU32,
                 libc::FUTEX_WAIT_BITSET | libc::FUTEX_PRIVATE_FLAG,
                 expected,
                 timespec.as_ref().map_or(null(), |t| &t.t as *const libc::timespec),
@@ -53,10 +53,10 @@ pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option<Duration>) -
 }
 
 #[cfg(target_os = "emscripten")]
-pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option<Duration>) {
+pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) {
     extern "C" {
         fn emscripten_futex_wait(
-            addr: *const AtomicI32,
+            addr: *const AtomicU32,
             val: libc::c_uint,
             max_wait_ms: libc::c_double,
         ) -> libc::c_int;
@@ -64,10 +64,8 @@ pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option<Duration>) {
 
     unsafe {
         emscripten_futex_wait(
-            futex as *const AtomicI32,
-            // `val` is declared unsigned to match the Emscripten headers, but since it's used as
-            // an opaque value, we can ignore the meaning of signed vs. unsigned and cast here.
-            expected as libc::c_uint,
+            futex,
+            expected,
             timeout.map_or(crate::f64::INFINITY, |d| d.as_secs_f64() * 1000.0),
         );
     }
@@ -78,11 +76,11 @@ pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option<Duration>) {
 /// Returns true if this actually woke up such a thread,
 /// or false if no thread was waiting on this futex.
 #[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn futex_wake(futex: &AtomicI32) -> bool {
+pub fn futex_wake(futex: &AtomicU32) -> bool {
     unsafe {
         libc::syscall(
             libc::SYS_futex,
-            futex as *const AtomicI32,
+            futex as *const AtomicU32,
             libc::FUTEX_WAKE | libc::FUTEX_PRIVATE_FLAG,
             1,
         ) > 0
@@ -91,11 +89,11 @@ pub fn futex_wake(futex: &AtomicI32) -> bool {
 
 /// Wake up all threads that are waiting on futex_wait on this futex.
 #[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn futex_wake_all(futex: &AtomicI32) {
+pub fn futex_wake_all(futex: &AtomicU32) {
     unsafe {
         libc::syscall(
             libc::SYS_futex,
-            futex as *const AtomicI32,
+            futex as *const AtomicU32,
             libc::FUTEX_WAKE | libc::FUTEX_PRIVATE_FLAG,
             i32::MAX,
         );
@@ -103,10 +101,10 @@ pub fn futex_wake_all(futex: &AtomicI32) {
 }
 
 #[cfg(target_os = "emscripten")]
-pub fn futex_wake(futex: &AtomicI32) -> bool {
+pub fn futex_wake(futex: &AtomicU32) -> bool {
     extern "C" {
-        fn emscripten_futex_wake(addr: *const AtomicI32, count: libc::c_int) -> libc::c_int;
+        fn emscripten_futex_wake(addr: *const AtomicU32, count: libc::c_int) -> libc::c_int;
     }
 
-    unsafe { emscripten_futex_wake(futex as *const AtomicI32, 1) > 0 }
+    unsafe { emscripten_futex_wake(futex, 1) > 0 }
 }
diff --git a/library/std/src/sys/unix/locks/futex.rs b/library/std/src/sys/unix/locks/futex.rs
index d97777e4da29d..b166e7c453cad 100644
--- a/library/std/src/sys/unix/locks/futex.rs
+++ b/library/std/src/sys/unix/locks/futex.rs
@@ -1,6 +1,6 @@
 use crate::cell::UnsafeCell;
 use crate::sync::atomic::{
-    AtomicI32, AtomicUsize,
+    AtomicU32, AtomicUsize,
     Ordering::{Acquire, Relaxed, Release},
 };
 use crate::sys::futex::{futex_wait, futex_wake, futex_wake_all};
@@ -13,13 +13,13 @@ pub struct Mutex {
     /// 0: unlocked
     /// 1: locked, no other threads waiting
     /// 2: locked, and other threads waiting (contended)
-    futex: AtomicI32,
+    futex: AtomicU32,
 }
 
 impl Mutex {
     #[inline]
     pub const fn new() -> Self {
-        Self { futex: AtomicI32::new(0) }
+        Self { futex: AtomicU32::new(0) }
     }
 
     #[inline]
@@ -71,7 +71,7 @@ impl Mutex {
         }
     }
 
-    fn spin(&self) -> i32 {
+    fn spin(&self) -> u32 {
         let mut spin = 100;
         loop {
             // We only use `load` (and not `swap` or `compare_exchange`)
@@ -110,13 +110,13 @@ pub struct Condvar {
     // The value of this atomic is simply incremented on every notification.
     // This is used by `.wait()` to not miss any notifications after
     // unlocking the mutex and before waiting for notifications.
-    futex: AtomicI32,
+    futex: AtomicU32,
 }
 
 impl Condvar {
     #[inline]
     pub const fn new() -> Self {
-        Self { futex: AtomicI32::new(0) }
+        Self { futex: AtomicU32::new(0) }
     }
 
     #[inline]
diff --git a/library/std/src/sys/unix/locks/futex_rwlock.rs b/library/std/src/sys/unix/locks/futex_rwlock.rs
index aa16da97e4c19..e42edb2585834 100644
--- a/library/std/src/sys/unix/locks/futex_rwlock.rs
+++ b/library/std/src/sys/unix/locks/futex_rwlock.rs
@@ -1,5 +1,5 @@
 use crate::sync::atomic::{
-    AtomicI32,
+    AtomicU32,
     Ordering::{Acquire, Relaxed, Release},
 };
 use crate::sys::futex::{futex_wait, futex_wake, futex_wake_all};
@@ -14,36 +14,36 @@ pub struct RwLock {
     //   0x3FFF_FFFF: Write locked
     // Bit 30: Readers are waiting on this futex.
     // Bit 31: Writers are waiting on the writer_notify futex.
-    state: AtomicI32,
+    state: AtomicU32,
     // The 'condition variable' to notify writers through.
     // Incremented on every signal.
-    writer_notify: AtomicI32,
+    writer_notify: AtomicU32,
 }
 
-const READ_LOCKED: i32 = 1;
-const MASK: i32 = (1 << 30) - 1;
-const WRITE_LOCKED: i32 = MASK;
-const MAX_READERS: i32 = MASK - 1;
-const READERS_WAITING: i32 = 1 << 30;
-const WRITERS_WAITING: i32 = 1 << 31;
+const READ_LOCKED: u32 = 1;
+const MASK: u32 = (1 << 30) - 1;
+const WRITE_LOCKED: u32 = MASK;
+const MAX_READERS: u32 = MASK - 1;
+const READERS_WAITING: u32 = 1 << 30;
+const WRITERS_WAITING: u32 = 1 << 31;
 
-fn is_unlocked(state: i32) -> bool {
+fn is_unlocked(state: u32) -> bool {
     state & MASK == 0
 }
 
-fn is_write_locked(state: i32) -> bool {
+fn is_write_locked(state: u32) -> bool {
     state & MASK == WRITE_LOCKED
 }
 
-fn has_readers_waiting(state: i32) -> bool {
+fn has_readers_waiting(state: u32) -> bool {
     state & READERS_WAITING != 0
 }
 
-fn has_writers_waiting(state: i32) -> bool {
+fn has_writers_waiting(state: u32) -> bool {
     state & WRITERS_WAITING != 0
 }
 
-fn is_read_lockable(state: i32) -> bool {
+fn is_read_lockable(state: u32) -> bool {
     // This also returns false if the counter could overflow if we tried to read lock it.
     //
     // We don't allow read-locking if there's readers waiting, even if the lock is unlocked
@@ -53,14 +53,14 @@ fn is_read_lockable(state: i32) -> bool {
     state & MASK < MAX_READERS && !has_readers_waiting(state) && !has_writers_waiting(state)
 }
 
-fn has_reached_max_readers(state: i32) -> bool {
+fn has_reached_max_readers(state: u32) -> bool {
     state & MASK == MAX_READERS
 }
 
 impl RwLock {
     #[inline]
     pub const fn new() -> Self {
-        Self { state: AtomicI32::new(0), writer_notify: AtomicI32::new(0) }
+        Self { state: AtomicU32::new(0), writer_notify: AtomicU32::new(0) }
     }
 
     #[inline]
@@ -227,7 +227,7 @@ impl RwLock {
     /// If both are waiting, this will wake up only one writer, but will fall
     /// back to waking up readers if there was no writer to wake up.
     #[cold]
-    fn wake_writer_or_readers(&self, mut state: i32) {
+    fn wake_writer_or_readers(&self, mut state: u32) {
         assert!(is_unlocked(state));
 
         // The readers waiting bit might be turned on at any point now,
@@ -287,7 +287,7 @@ impl RwLock {
     }
 
     /// Spin for a while, but stop directly at the given condition.
-    fn spin_until(&self, f: impl Fn(i32) -> bool) -> i32 {
+    fn spin_until(&self, f: impl Fn(u32) -> bool) -> u32 {
         let mut spin = 100; // Chosen by fair dice roll.
         loop {
             let state = self.state.load(Relaxed);
@@ -299,12 +299,12 @@ impl RwLock {
         }
     }
 
-    fn spin_write(&self) -> i32 {
+    fn spin_write(&self) -> u32 {
         // Stop spinning when it's unlocked or when there's waiting writers, to keep things somewhat fair.
         self.spin_until(|state| is_unlocked(state) || has_writers_waiting(state))
     }
 
-    fn spin_read(&self) -> i32 {
+    fn spin_read(&self) -> u32 {
         // Stop spinning when it's unlocked or read locked, or when there's waiting threads.
         self.spin_until(|state| {
             !is_write_locked(state) || has_readers_waiting(state) || has_writers_waiting(state)
diff --git a/library/std/src/sys/wasm/atomics/futex.rs b/library/std/src/sys/wasm/atomics/futex.rs
index 3d8bf42f7255e..bbe9bd6951af9 100644
--- a/library/std/src/sys/wasm/atomics/futex.rs
+++ b/library/std/src/sys/wasm/atomics/futex.rs
@@ -1,17 +1,21 @@
 use crate::arch::wasm32;
 use crate::convert::TryInto;
-use crate::sync::atomic::AtomicI32;
+use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
-pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option<Duration>) {
+pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) {
     let timeout = timeout.and_then(|t| t.as_nanos().try_into().ok()).unwrap_or(-1);
     unsafe {
-        wasm32::memory_atomic_wait32(futex as *const AtomicI32 as *mut i32, expected, timeout);
+        wasm32::memory_atomic_wait32(
+            futex as *const AtomicU32 as *mut i32,
+            expected as i32,
+            timeout,
+        );
     }
 }
 
-pub fn futex_wake(futex: &AtomicI32) {
+pub fn futex_wake(futex: &AtomicU32) {
     unsafe {
-        wasm32::memory_atomic_notify(futex as *const AtomicI32 as *mut i32, 1);
+        wasm32::memory_atomic_notify(futex as *const AtomicU32 as *mut i32, 1);
     }
 }
diff --git a/library/std/src/sys_common/thread_parker/futex.rs b/library/std/src/sys_common/thread_parker/futex.rs
index 0132743b24404..fbf6231ff4ab3 100644
--- a/library/std/src/sys_common/thread_parker/futex.rs
+++ b/library/std/src/sys_common/thread_parker/futex.rs
@@ -1,14 +1,14 @@
-use crate::sync::atomic::AtomicI32;
+use crate::sync::atomic::AtomicU32;
 use crate::sync::atomic::Ordering::{Acquire, Release};
 use crate::sys::futex::{futex_wait, futex_wake};
 use crate::time::Duration;
 
-const PARKED: i32 = -1;
-const EMPTY: i32 = 0;
-const NOTIFIED: i32 = 1;
+const PARKED: u32 = u32::MAX;
+const EMPTY: u32 = 0;
+const NOTIFIED: u32 = 1;
 
 pub struct Parker {
-    state: AtomicI32,
+    state: AtomicU32,
 }
 
 // Notes about memory ordering:
@@ -34,7 +34,7 @@ pub struct Parker {
 impl Parker {
     #[inline]
     pub const fn new() -> Self {
-        Parker { state: AtomicI32::new(EMPTY) }
+        Parker { state: AtomicU32::new(EMPTY) }
     }
 
     // Assumes this is only called by the thread that owns the Parker,
diff --git a/src/doc/book b/src/doc/book
index ea90bbaf53ba6..765318b844569 160000
--- a/src/doc/book
+++ b/src/doc/book
@@ -1 +1 @@
-Subproject commit ea90bbaf53ba64ef4e2da9ac2352b298aec6bec8
+Subproject commit 765318b844569a642ceef7bf1adab9639cbf6af3
diff --git a/src/doc/nomicon b/src/doc/nomicon
index 11f1165e8a2f5..c7d8467ca9158 160000
--- a/src/doc/nomicon
+++ b/src/doc/nomicon
@@ -1 +1 @@
-Subproject commit 11f1165e8a2f5840467e748c8108dc53c948ee9a
+Subproject commit c7d8467ca9158da58ef295ae65dbf00a308752d9
diff --git a/src/doc/reference b/src/doc/reference
index c97d14fa6fed0..b5f6c2362baf9 160000
--- a/src/doc/reference
+++ b/src/doc/reference
@@ -1 +1 @@
-Subproject commit c97d14fa6fed0baa9255432b8a93cb70614f80e3
+Subproject commit b5f6c2362baf932db9440fbfcb509b309237ee85
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
index ec954f35eedf5..c2a98d9fc5d29 160000
--- a/src/doc/rust-by-example
+++ b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit ec954f35eedf592cd173b21c05a7f80a65b61d8a
+Subproject commit c2a98d9fc5d29c481d42052fbeccfde15ed03116
diff --git a/src/doc/rustc-dev-guide b/src/doc/rustc-dev-guide
index 155126b1d2e2c..eeb5a83c15b6a 160000
--- a/src/doc/rustc-dev-guide
+++ b/src/doc/rustc-dev-guide
@@ -1 +1 @@
-Subproject commit 155126b1d2e2cb01ddb1d7ba9489b90d7cd173ad
+Subproject commit eeb5a83c15b6ae60df3e4f19207376b22c6fbc4c
diff --git a/src/librustdoc/html/render/span_map.rs b/src/librustdoc/html/render/span_map.rs
index 731e18b1eec2c..06c63ec97d7f2 100644
--- a/src/librustdoc/html/render/span_map.rs
+++ b/src/librustdoc/html/render/span_map.rs
@@ -119,11 +119,14 @@ impl<'tcx> Visitor<'tcx> for SpanMapVisitor<'tcx> {
     fn visit_mod(&mut self, m: &'tcx Mod<'tcx>, span: Span, id: HirId) {
         // To make the difference between "mod foo {}" and "mod foo;". In case we "import" another
         // file, we want to link to it. Otherwise no need to create a link.
-        if !span.overlaps(m.inner) {
+        if !span.overlaps(m.spans.inner_span) {
             // Now that we confirmed it's a file import, we want to get the span for the module
             // name only and not all the "mod foo;".
             if let Some(Node::Item(item)) = self.tcx.hir().find(id) {
-                self.matches.insert(item.ident.span, LinkFromSrc::Local(clean::Span::new(m.inner)));
+                self.matches.insert(
+                    item.ident.span,
+                    LinkFromSrc::Local(clean::Span::new(m.spans.inner_span)),
+                );
             }
         }
         intravisit::walk_mod(self, m, id);
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index e793ee75fd2e0..75276d18fe5e9 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -154,7 +154,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         m: &'tcx hir::Mod<'tcx>,
         name: Symbol,
     ) -> Module<'tcx> {
-        let mut om = Module::new(name, id, m.inner);
+        let mut om = Module::new(name, id, m.spans.inner_span);
         let def_id = self.cx.tcx.hir().local_def_id(id).to_def_id();
         // Keep track of if there were any private modules in the path.
         let orig_inside_public_path = self.inside_public_path;
diff --git a/src/test/ui/deriving/deriving-default-enum.rs b/src/test/ui/deriving/deriving-default-enum.rs
index 931ff1a5847d4..d1a81c72c2fdc 100644
--- a/src/test/ui/deriving/deriving-default-enum.rs
+++ b/src/test/ui/deriving/deriving-default-enum.rs
@@ -1,7 +1,5 @@
 // run-pass
 
-#![feature(derive_default_enum)]
-
 // nb: does not impl Default
 #[derive(Debug, PartialEq)]
 struct NotDefault;
diff --git a/src/test/ui/deriving/deriving-with-helper.rs b/src/test/ui/deriving/deriving-with-helper.rs
index d8f0b27a2e5f6..1c30b0b6fba75 100644
--- a/src/test/ui/deriving/deriving-with-helper.rs
+++ b/src/test/ui/deriving/deriving-with-helper.rs
@@ -5,7 +5,6 @@
 #![feature(lang_items)]
 #![feature(no_core)]
 #![feature(rustc_attrs)]
-#![feature(derive_default_enum)]
 
 #![no_core]
 
diff --git a/src/test/ui/feature-gates/feature-gate-derive_default_enum.rs b/src/test/ui/feature-gates/feature-gate-derive_default_enum.rs
deleted file mode 100644
index 05a5d4e14223a..0000000000000
--- a/src/test/ui/feature-gates/feature-gate-derive_default_enum.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-#[derive(Default)] //~ ERROR deriving `Default` on enums is experimental
-enum Foo {
-    #[default]
-    Alpha,
-}
-
-fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-derive_default_enum.stderr b/src/test/ui/feature-gates/feature-gate-derive_default_enum.stderr
deleted file mode 100644
index 58dd4d508a709..0000000000000
--- a/src/test/ui/feature-gates/feature-gate-derive_default_enum.stderr
+++ /dev/null
@@ -1,13 +0,0 @@
-error[E0658]: deriving `Default` on enums is experimental
-  --> $DIR/feature-gate-derive_default_enum.rs:1:10
-   |
-LL | #[derive(Default)]
-   |          ^^^^^^^
-   |
-   = note: see issue #86985 <https://github.com/rust-lang/rust/issues/86985> for more information
-   = help: add `#![feature(derive_default_enum)]` to the crate attributes to enable
-   = note: this error originates in the derive macro `Default` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/imports/overlapping_pub_trait.rs b/src/test/ui/imports/overlapping_pub_trait.rs
index f5f5d4ed3804f..69aba3ae9b4e7 100644
--- a/src/test/ui/imports/overlapping_pub_trait.rs
+++ b/src/test/ui/imports/overlapping_pub_trait.rs
@@ -4,10 +4,10 @@
  * This crate declares two public paths, `m::Tr` and `prelude::_`. Make sure we prefer the former.
  */
 extern crate overlapping_pub_trait_source;
+//~^ HELP the following trait is implemented but not in scope; perhaps add a `use` for it:
+//~| SUGGESTION overlapping_pub_trait_source::m::Tr
 
 fn main() {
-    //~^ HELP the following trait is implemented but not in scope; perhaps add a `use` for it:
-    //~| SUGGESTION overlapping_pub_trait_source::m::Tr
     use overlapping_pub_trait_source::S;
     S.method();
     //~^ ERROR no method named `method` found for struct `S` in the current scope [E0599]
diff --git a/src/test/ui/imports/unnamed_pub_trait.rs b/src/test/ui/imports/unnamed_pub_trait.rs
index b06b1e1d07dce..c38fb17b97649 100644
--- a/src/test/ui/imports/unnamed_pub_trait.rs
+++ b/src/test/ui/imports/unnamed_pub_trait.rs
@@ -5,10 +5,10 @@
  * importing it by name, and instead we suggest importing it by glob.
  */
 extern crate unnamed_pub_trait_source;
+//~^ HELP the following trait is implemented but not in scope; perhaps add a `use` for it:
+//~| SUGGESTION unnamed_pub_trait_source::prelude::*; // trait Tr
 
 fn main() {
-    //~^ HELP the following trait is implemented but not in scope; perhaps add a `use` for it:
-    //~| SUGGESTION unnamed_pub_trait_source::prelude::*; // trait Tr
     use unnamed_pub_trait_source::S;
     S.method();
     //~^ ERROR no method named `method` found for struct `S` in the current scope [E0599]
diff --git a/src/test/ui/macros/macros-nonfatal-errors.rs b/src/test/ui/macros/macros-nonfatal-errors.rs
index 98f64aa6f8025..e7a01f105de0b 100644
--- a/src/test/ui/macros/macros-nonfatal-errors.rs
+++ b/src/test/ui/macros/macros-nonfatal-errors.rs
@@ -5,7 +5,6 @@
 
 #![feature(trace_macros, concat_idents)]
 #![feature(stmt_expr_attributes, arbitrary_enum_discriminant)]
-#![feature(derive_default_enum)]
 
 use std::arch::asm;
 
diff --git a/src/test/ui/macros/macros-nonfatal-errors.stderr b/src/test/ui/macros/macros-nonfatal-errors.stderr
index 79e8db9c1d429..b3c6d07f96763 100644
--- a/src/test/ui/macros/macros-nonfatal-errors.stderr
+++ b/src/test/ui/macros/macros-nonfatal-errors.stderr
@@ -1,41 +1,41 @@
 error: the `#[default]` attribute may only be used on unit enum variants
-  --> $DIR/macros-nonfatal-errors.rs:14:5
+  --> $DIR/macros-nonfatal-errors.rs:13:5
    |
 LL |     #[default]
    |     ^^^^^^^^^^
 
 error: the `#[default]` attribute may only be used on unit enum variants
-  --> $DIR/macros-nonfatal-errors.rs:19:36
+  --> $DIR/macros-nonfatal-errors.rs:18:36
    |
 LL | struct DefaultInnerAttrTupleStruct(#[default] ());
    |                                    ^^^^^^^^^^
 
 error: the `#[default]` attribute may only be used on unit enum variants
-  --> $DIR/macros-nonfatal-errors.rs:23:1
+  --> $DIR/macros-nonfatal-errors.rs:22:1
    |
 LL | #[default]
    | ^^^^^^^^^^
 
 error: the `#[default]` attribute may only be used on unit enum variants
-  --> $DIR/macros-nonfatal-errors.rs:27:1
+  --> $DIR/macros-nonfatal-errors.rs:26:1
    |
 LL | #[default]
    | ^^^^^^^^^^
 
 error: the `#[default]` attribute may only be used on unit enum variants
-  --> $DIR/macros-nonfatal-errors.rs:37:11
+  --> $DIR/macros-nonfatal-errors.rs:36:11
    |
 LL |     Foo = #[default] 0,
    |           ^^^^^^^^^^
 
 error: the `#[default]` attribute may only be used on unit enum variants
-  --> $DIR/macros-nonfatal-errors.rs:38:14
+  --> $DIR/macros-nonfatal-errors.rs:37:14
    |
 LL |     Bar([u8; #[default] 1]),
    |              ^^^^^^^^^^
 
 error: no default declared
-  --> $DIR/macros-nonfatal-errors.rs:43:10
+  --> $DIR/macros-nonfatal-errors.rs:42:10
    |
 LL | #[derive(Default)]
    |          ^^^^^^^
@@ -44,7 +44,7 @@ LL | #[derive(Default)]
    = note: this error originates in the derive macro `Default` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: multiple declared defaults
-  --> $DIR/macros-nonfatal-errors.rs:49:10
+  --> $DIR/macros-nonfatal-errors.rs:48:10
    |
 LL | #[derive(Default)]
    |          ^^^^^^^
@@ -62,7 +62,7 @@ LL |     Baz,
    = note: this error originates in the derive macro `Default` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: `#[default]` attribute does not accept a value
-  --> $DIR/macros-nonfatal-errors.rs:61:5
+  --> $DIR/macros-nonfatal-errors.rs:60:5
    |
 LL |     #[default = 1]
    |     ^^^^^^^^^^^^^^
@@ -70,7 +70,7 @@ LL |     #[default = 1]
    = help: try using `#[default]`
 
 error: multiple `#[default]` attributes
-  --> $DIR/macros-nonfatal-errors.rs:69:5
+  --> $DIR/macros-nonfatal-errors.rs:68:5
    |
 LL |     #[default]
    |     ---------- `#[default]` used here
@@ -81,13 +81,13 @@ LL |     Foo,
    |
    = note: only one `#[default]` attribute is needed
 help: try removing this
-  --> $DIR/macros-nonfatal-errors.rs:68:5
+  --> $DIR/macros-nonfatal-errors.rs:67:5
    |
 LL |     #[default]
    |     ^^^^^^^^^^
 
 error: multiple `#[default]` attributes
-  --> $DIR/macros-nonfatal-errors.rs:79:5
+  --> $DIR/macros-nonfatal-errors.rs:78:5
    |
 LL |     #[default]
    |     ---------- `#[default]` used here
@@ -99,7 +99,7 @@ LL |     Foo,
    |
    = note: only one `#[default]` attribute is needed
 help: try removing these
-  --> $DIR/macros-nonfatal-errors.rs:76:5
+  --> $DIR/macros-nonfatal-errors.rs:75:5
    |
 LL |     #[default]
    |     ^^^^^^^^^^
@@ -109,7 +109,7 @@ LL |     #[default]
    |     ^^^^^^^^^^
 
 error: the `#[default]` attribute may only be used on unit enum variants
-  --> $DIR/macros-nonfatal-errors.rs:86:5
+  --> $DIR/macros-nonfatal-errors.rs:85:5
    |
 LL |     Foo {},
    |     ^^^
@@ -117,7 +117,7 @@ LL |     Foo {},
    = help: consider a manual implementation of `Default`
 
 error: default variant must be exhaustive
-  --> $DIR/macros-nonfatal-errors.rs:94:5
+  --> $DIR/macros-nonfatal-errors.rs:93:5
    |
 LL |     #[non_exhaustive]
    |     ----------------- declared `#[non_exhaustive]` here
@@ -127,37 +127,37 @@ LL |     Foo,
    = help: consider a manual implementation of `Default`
 
 error: asm template must be a string literal
-  --> $DIR/macros-nonfatal-errors.rs:99:10
+  --> $DIR/macros-nonfatal-errors.rs:98:10
    |
 LL |     asm!(invalid);
    |          ^^^^^^^
 
 error: concat_idents! requires ident args
-  --> $DIR/macros-nonfatal-errors.rs:102:5
+  --> $DIR/macros-nonfatal-errors.rs:101:5
    |
 LL |     concat_idents!("not", "idents");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: argument must be a string literal
-  --> $DIR/macros-nonfatal-errors.rs:104:17
+  --> $DIR/macros-nonfatal-errors.rs:103:17
    |
 LL |     option_env!(invalid);
    |                 ^^^^^^^
 
 error: expected string literal
-  --> $DIR/macros-nonfatal-errors.rs:105:10
+  --> $DIR/macros-nonfatal-errors.rs:104:10
    |
 LL |     env!(invalid);
    |          ^^^^^^^
 
 error: expected string literal
-  --> $DIR/macros-nonfatal-errors.rs:106:10
+  --> $DIR/macros-nonfatal-errors.rs:105:10
    |
 LL |     env!(foo, abr, baz);
    |          ^^^
 
 error: environment variable `RUST_HOPEFULLY_THIS_DOESNT_EXIST` not defined
-  --> $DIR/macros-nonfatal-errors.rs:107:5
+  --> $DIR/macros-nonfatal-errors.rs:106:5
    |
 LL |     env!("RUST_HOPEFULLY_THIS_DOESNT_EXIST");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -165,7 +165,7 @@ LL |     env!("RUST_HOPEFULLY_THIS_DOESNT_EXIST");
    = note: this error originates in the macro `env` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: format argument must be a string literal
-  --> $DIR/macros-nonfatal-errors.rs:109:13
+  --> $DIR/macros-nonfatal-errors.rs:108:13
    |
 LL |     format!(invalid);
    |             ^^^^^^^
@@ -176,19 +176,19 @@ LL |     format!("{}", invalid);
    |             +++++
 
 error: argument must be a string literal
-  --> $DIR/macros-nonfatal-errors.rs:111:14
+  --> $DIR/macros-nonfatal-errors.rs:110:14
    |
 LL |     include!(invalid);
    |              ^^^^^^^
 
 error: argument must be a string literal
-  --> $DIR/macros-nonfatal-errors.rs:113:18
+  --> $DIR/macros-nonfatal-errors.rs:112:18
    |
 LL |     include_str!(invalid);
    |                  ^^^^^^^
 
 error: couldn't read $DIR/i'd be quite surprised if a file with this name existed: $FILE_NOT_FOUND_MSG (os error 2)
-  --> $DIR/macros-nonfatal-errors.rs:114:5
+  --> $DIR/macros-nonfatal-errors.rs:113:5
    |
 LL |     include_str!("i'd be quite surprised if a file with this name existed");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -196,13 +196,13 @@ LL |     include_str!("i'd be quite surprised if a file with this name existed")
    = note: this error originates in the macro `include_str` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: argument must be a string literal
-  --> $DIR/macros-nonfatal-errors.rs:115:20
+  --> $DIR/macros-nonfatal-errors.rs:114:20
    |
 LL |     include_bytes!(invalid);
    |                    ^^^^^^^
 
 error: couldn't read $DIR/i'd be quite surprised if a file with this name existed: $FILE_NOT_FOUND_MSG (os error 2)
-  --> $DIR/macros-nonfatal-errors.rs:116:5
+  --> $DIR/macros-nonfatal-errors.rs:115:5
    |
 LL |     include_bytes!("i'd be quite surprised if a file with this name existed");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -210,13 +210,13 @@ LL |     include_bytes!("i'd be quite surprised if a file with this name existed
    = note: this error originates in the macro `include_bytes` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: trace_macros! accepts only `true` or `false`
-  --> $DIR/macros-nonfatal-errors.rs:118:5
+  --> $DIR/macros-nonfatal-errors.rs:117:5
    |
 LL |     trace_macros!(invalid);
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: cannot find macro `llvm_asm` in this scope
-  --> $DIR/macros-nonfatal-errors.rs:100:5
+  --> $DIR/macros-nonfatal-errors.rs:99:5
    |
 LL |     llvm_asm!(invalid);
    |     ^^^^^^^^
diff --git a/src/test/ui/mir/issue-95978-validator-lifetime-comparison.rs b/src/test/ui/mir/issue-95978-validator-lifetime-comparison.rs
new file mode 100644
index 0000000000000..cd6c5bf271935
--- /dev/null
+++ b/src/test/ui/mir/issue-95978-validator-lifetime-comparison.rs
@@ -0,0 +1,10 @@
+// check-pass
+// compile-flags: -Zvalidate-mir
+
+fn foo(_a: &str) {}
+
+fn main() {
+    let x = foo as fn(&'static str);
+
+    let _ = x == foo;
+}
diff --git a/src/test/ui/suggestions/use-placement-typeck.fixed b/src/test/ui/suggestions/use-placement-typeck.fixed
index 40c55d1dd06bc..37335da060e42 100644
--- a/src/test/ui/suggestions/use-placement-typeck.fixed
+++ b/src/test/ui/suggestions/use-placement-typeck.fixed
@@ -7,7 +7,6 @@
 #![allow(unused)]
 
 use m::Foo;
-
 fn main() {
     let s = m::S;
     s.abc(); //~ ERROR no method named `abc`
diff --git a/src/test/ui/thread-local/non-static.rs b/src/test/ui/thread-local/non-static.rs
new file mode 100644
index 0000000000000..f1c4273870bff
--- /dev/null
+++ b/src/test/ui/thread-local/non-static.rs
@@ -0,0 +1,30 @@
+// Check that #[thread_local] attribute is rejected on non-static items.
+#![feature(thread_local)]
+
+#[thread_local]
+//~^ ERROR attribute should be applied to a static
+const A: u32 = 0;
+
+#[thread_local]
+//~^ ERROR attribute should be applied to a static
+fn main() {
+    #[thread_local] || {};
+    //~^ ERROR attribute should be applied to a static
+}
+
+struct S {
+    #[thread_local]
+    //~^ ERROR attribute should be applied to a static
+    a: String,
+    b: String,
+}
+
+#[thread_local]
+// Static. OK.
+static B: u32 = 0;
+
+extern "C" {
+    #[thread_local]
+    // Foreign static. OK.
+    static C: u32;
+}
diff --git a/src/test/ui/thread-local/non-static.stderr b/src/test/ui/thread-local/non-static.stderr
new file mode 100644
index 0000000000000..09a1618d6e710
--- /dev/null
+++ b/src/test/ui/thread-local/non-static.stderr
@@ -0,0 +1,38 @@
+error: attribute should be applied to a static
+  --> $DIR/non-static.rs:4:1
+   |
+LL | #[thread_local]
+   | ^^^^^^^^^^^^^^^
+LL |
+LL | const A: u32 = 0;
+   | ----------------- not a static
+
+error: attribute should be applied to a static
+  --> $DIR/non-static.rs:8:1
+   |
+LL |   #[thread_local]
+   |   ^^^^^^^^^^^^^^^
+LL |
+LL | / fn main() {
+LL | |     #[thread_local] || {};
+LL | |
+LL | | }
+   | |_- not a static
+
+error: attribute should be applied to a static
+  --> $DIR/non-static.rs:11:5
+   |
+LL |     #[thread_local] || {};
+   |     ^^^^^^^^^^^^^^^ ----- not a static
+
+error: attribute should be applied to a static
+  --> $DIR/non-static.rs:16:5
+   |
+LL |     #[thread_local]
+   |     ^^^^^^^^^^^^^^^
+LL |
+LL |     a: String,
+   |     --------- not a static
+
+error: aborting due to 4 previous errors
+
diff --git a/src/test/ui/unterminated-nested-comment.rs b/src/test/ui/unterminated-nested-comment.rs
new file mode 100644
index 0000000000000..db5f2f3ba1358
--- /dev/null
+++ b/src/test/ui/unterminated-nested-comment.rs
@@ -0,0 +1,4 @@
+/* //~ ERROR E0758
+/* */
+/*
+*/
diff --git a/src/test/ui/unterminated-nested-comment.stderr b/src/test/ui/unterminated-nested-comment.stderr
new file mode 100644
index 0000000000000..3653e76c9cbda
--- /dev/null
+++ b/src/test/ui/unterminated-nested-comment.stderr
@@ -0,0 +1,21 @@
+error[E0758]: unterminated block comment
+  --> $DIR/unterminated-nested-comment.rs:1:1
+   |
+LL |   /*
+   |   ^-
+   |   |
+   |  _unterminated block comment
+   | |
+LL | | /* */
+LL | | /*
+   | | --
+   | | |
+   | | ...as last nested comment starts here, maybe you want to close this instead?
+LL | | */
+   | |_--^
+   |   |
+   |   ...and last nested comment terminates here.
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0758`.