Co-authored-by: Yuki Okushi <huyuumi.dev@gmail.com>

This change was backed out in rust-lang#83412 so we should remove the reference
to it from the release notes.

THis came up in the review of rust-lang#83425: it's hard to imagine a use of
LLVM_VERSION_LE() or LLVM_VERSION_EQ() that's not asking for trouble
when a point release gets created, so let's just discard them to prevent
the issue.

stabilize debug_non_exhaustive

tracking issue: rust-lang#67364

but it is still an open question whether the other `Debug*` struct's should have a similar method. I would guess that would best be put underneath a new feature gate, as this one seems uncontroversial enough to stabilize as is

Remove Option::{unwrap_none, expect_none}.

This removes `Option::unwrap_none` and `Option::expect_none` since we're not going to stabilize them, see rust-lang#62633.

Closes rust-lang#62633

…c, r=CraftSpider

Add documentation for rustdoc-gui tests

I think a bit of documentation doesn't hurt in this case considering how "out of the ordinary" this is.

r? ``@jyn514``

Add Result::into_err where the Ok variant is the never type

Equivalent of rust-lang#66045 but for the inverse situation where `T: Into<!>` rather than `E: Into<!>`.

I'm using the same feature gate name. I can't see why one of these methods would be OK to stabilize but not the other.

Tracking issue: rust-lang#61695

small cleanups in rustc_errors / emitter

This is either moving code around so it gets called less often or using if let instead of match in a few cases.

…-Simulacrum

Update RELEASES.md

This change was backed out in rust-lang#83412 so we should remove the reference
to it from the release notes.

…n514

Use intra-doc link in core::cell

``@rustbot`` label T-doc A-intra-doc-links

r? ``@jyn514``

… r=cuviper

LLVMWrapper: attractive nuisance macros

This came up in the review of rust-lang#83425: it's hard to imagine a use of
LLVM_VERSION_LE() or LLVM_VERSION_EQ() that's not asking for trouble
when a point release gets created, so let's just discard them to prevent
the issue.