Auto merge of #64883 - Centril:rollup-uehjt63, r=Centril

Rollup of 10 pull requests

Successful merges:

 - #64131 (data_structures: Add deterministic FxHashMap and FxHashSet wrappers)
 - #64387 (Fix redundant semicolon lint interaction with proc macro attributes)
 - #64678 (added more context for duplicate lang item errors (fixes #60561))
 - #64763 (Add E0734 and its long explanation)
 - #64793 (Fix format macro expansions spans to be macro-generated)
 - #64837 (Improve wording in documentation of MaybeUninit)
 - #64852 (Print ParamTy span when accessing a field (#52082))
 - #64875 (Upgrade async/await to "used" keywords.)
 - #64876 (Fix typo in intrinsics op safety)
 - #64880 (Slice docs: fix typo)

Failed merges:

r? @ghost

Author: bors

src/libcore/mem/maybe_uninit.rs

@@ -5,12 +5,12 @@ use crate::mem::ManuallyDrop;
 ///
 /// # Initialization invariant
 ///
-/// The compiler, in general, assumes that variables are properly initialized
-/// at their respective type. For example, a variable of reference type must
-/// be aligned and non-NULL. This is an invariant that must *always* be upheld,
-/// even in unsafe code. As a consequence, zero-initializing a variable of reference
-/// type causes instantaneous [undefined behavior][ub], no matter whether that reference
-/// ever gets used to access memory:
+/// The compiler, in general, assumes that a variable is properly initialized
+/// according to the requirements of the variable's type. For example, a variable of
+/// reference type must be aligned and non-NULL. This is an invariant that must
+/// *always* be upheld, even in unsafe code. As a consequence, zero-initializing a
+/// variable of reference type causes instantaneous [undefined behavior][ub],
+/// no matter whether that reference ever gets used to access memory:
 ///
 /// ```rust,no_run
 /// # #![allow(invalid_value)]

src/librustc/error_codes.rs

@@ -2217,6 +2217,23 @@ Examples of erroneous code:
 static X: u32 = 42;
 ```
 "##,
+
+E0734: r##"
+A stability attribute has been used outside of the standard library.
+
+Erroneous code examples:
+
+```compile_fail,E0734
+#[rustc_deprecated(since = "b", reason = "text")] // invalid
+#[stable(feature = "a", since = "b")] // invalid
+#[unstable(feature = "b", issue = "0")] // invalid
+fn foo(){}
+```
+
+These attributes are meant to only be used by the standard library and are
+rejected in your own crates.
+"##,
+
 ;
 //  E0006, // merged with E0005
 //  E0101, // replaced with E0282