Auto merge of #87434 - Manishearth:rollup-b09njin, r=Manishearth

Rollup of 9 pull requests

Successful merges:

 - #87348 (Fix span when suggesting to add an associated type bound)
 - #87359 (Remove detection of rustup and cargo in 'missing extern crate' diagnostics)
 - #87370 (Add support for powerpc-unknown-freebsd)
 - #87389 (Rename `known_attrs` to `expanded_inert_attrs` and move to rustc_expand)
 - #87395 (Clear up std::env::set_var panic section.)
 - #87403 (Implement `AssignToDroppingUnionField` in THIR unsafeck)
 - #87410 (Mark `format_args_nl` as `#[doc(hidden)]`)
 - #87419 (IEEE 754 is not an RFC)
 - #87422 (DOC: remove unnecessary feature crate attribute from example code)

Failed merges:

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

3 files changed, 4 insertions, 5 deletions

diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs
index 3ca8f27c79a..07ee589e29f 100644
--- a/library/core/src/macros/mod.rs
+++ b/library/core/src/macros/mod.rs
@@ -845,6 +845,7 @@ pub(crate) mod builtin {
                   language use and is subject to change"
     )]
     #[allow_internal_unstable(fmt_internals)]
+    #[doc(hidden)]
     #[rustc_builtin_macro]
     #[macro_export]
     macro_rules! format_args_nl {
diff --git a/library/core/src/mem/maybe_uninit.rs b/library/core/src/mem/maybe_uninit.rs
index 5122421ea8c..d3ebc1cebb6 100644
--- a/library/core/src/mem/maybe_uninit.rs
+++ b/library/core/src/mem/maybe_uninit.rs
@@ -461,7 +461,6 @@ impl<T> MaybeUninit<T> {
     /// With `write`, we can avoid the need to write through a raw pointer:
     ///
     /// ```rust
-    /// #![feature(maybe_uninit_extra)]
     /// use core::pin::Pin;
     /// use core::mem::MaybeUninit;
     ///
diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 64f88c1aba6..5709d97d643 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -294,7 +294,7 @@ impl Error for VarError {
     }
 }
 
-/// Sets the environment variable `k` to the value `v` for the currently running
+/// Sets the environment variable `key` to the value `value` for the currently running
 /// process.
 ///
 /// Note that while concurrent access to environment variables is safe in Rust,
@@ -310,9 +310,8 @@ impl Error for VarError {
 ///
 /// # Panics
 ///
-/// This function may panic if `key` is empty, contains an ASCII equals sign
-/// `'='` or the NUL character `'\0'`, or when the value contains the NUL
-/// character.
+/// This function may panic if `key` is empty, contains an ASCII equals sign `'='`
+/// or the NUL character `'\0'`, or when `value` contains the NUL character.
 ///
 /// # Examples
 ///