Auto merge of rust-lang#129946 - GuillaumeGomez:rollup-bovh08y, r=GuillaumeGomez

Rollup of 7 pull requests

Successful merges:

 - rust-lang#127021 (Add target support for RTEMS Arm)
 - rust-lang#128871 (bypass linker configuration and cross target check for specific commands)
 - rust-lang#129471 ([rustdoc] Sort impl associated items by kinds and then by appearance)
 - rust-lang#129529 (Add test to build crates used by r-a on stable)
 - rust-lang#129706 (Rename dump of coroutine by-move-body to be more consistent, fix ICE in dump_mir)
 - rust-lang#129796 (Unify scraped examples with other code examples)
 - rust-lang#129939 (explain why Rvalue::Len still exists)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_middle/src/mir/pretty.rs

@@ -612,7 +612,9 @@ fn write_mir_sig(tcx: TyCtxt<'_>, body: &Body<'_>, w: &mut dyn io::Write) -> io:
     let def_id = body.source.def_id();
     let kind = tcx.def_kind(def_id);
     let is_function = match kind {
-        DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(..) => true,
+        DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(..) | DefKind::SyntheticCoroutineBody => {
+            true
+        }
         _ => tcx.is_closure_like(def_id),
     };
     match (kind, body.source.promoted) {

compiler/rustc_middle/src/mir/syntax.rs

@@ -1307,6 +1307,9 @@ pub enum Rvalue<'tcx> {
     /// If the type of the place is an array, this is the array length. For slices (`[T]`, not
     /// `&[T]`) this accesses the place's metadata to determine the length. This rvalue is
     /// ill-formed for places of other types.
+    ///
+    /// This cannot be a `UnOp(PtrMetadata, _)` because that expects a value, and we only
+    /// have a place, and `UnOp(PtrMetadata, RawPtr(place))` is not a thing.
     Len(Place<'tcx>),
 
     /// Performs essentially all of the casts that can be performed via `as`.