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

2 files changed, 1 insertions, 1 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;
     ///