Since the `compiler_builtins` update [1], ABI bugs on x86 should be
resolved. Enable tests for f16 on these platforms now.

[1]: rust-lang#125016

Since `f16` now works on x86 and x86-64, change doctests to use this
instead of aarch64. This is to make sure any changes get run in PR CI.

and not the function/method call

1. Decouple them.
2. Make logic around `diagnostic_outside_of_impl`'s early exits simpler.
3. Make `untranslatable_diagnostic` run one loop instead of two
   and not allocate an intermediate vec.
4. Overall, reduce the amount of code executed
   when the lints do not end up firing.

This approach is, roughly, based on how Discourse does it.
It came up while discussing some other possible sidebar changes,
as a design that made rapid scanning easier while avoiding the
inherent trade-offs in summarizing.

`Cell` and `RefCell` have their `into_inner` methods const unstable.
`OnceCell` has the same logic, so add it under the same gate.

Tracking issue: rust-lang#78729

This makes it easier for maintainers to see what the Python script is for.

Trying to get rid of this Python script looks tempting, because it's currently
the only Python script in the whole `run-make` suite that we actually run.

But getting rid of it would require pulling in a Rust crate to parse XML
instead, and that's probably not worth the extra hassle for a relatively-minor
test.

…avidtwco

Implement `-Z embed-source` (DWARFv5 source code embedding extension)

Implement rust-lang/compiler-team#764 MCP which adds an unstable flag that exposes LLVM's [DWARFv5 source code embedding](https://dwarfstd.org/issues/180201.1.html) support.

use old ctx if has same expand environment during decode span

Fixes rust-lang#112680

The root reason why rust-lang#112680 failed with incremental compilation on the second attempt is the difference in `opaque` between the span of the field [`ident`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_hir_typeck/src/expr.rs#L2348) and the span in the incremental cache at `tcx.def_ident_span(field.did)`.

-  Let's call the span of `ident` as `span_a`, which is generated by [`apply_mark_internal`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_span/src/hygiene.rs#L553-L554). Its content is similar to:

```rs
span_a_ctx -> SyntaxContextData {
      opaque: span_a_ctx,
      opaque_and_semitransparent: span_a_ctx,
      // ....
}
```

- And call the span of `tcx.def_ident_span` as `span_b`, which is generated by [`decode_syntax_context`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_span/src/hygiene.rs#L1390). Its content is:

```rs
span_b_ctx -> SyntaxContextData {
      opaque: span_b_ctx,
      // note `span_b_ctx` is not same as `span_a_ctx`
      opaque_and_semitransparent: span_b_ctx,
      // ....
}
```

Although they have the same `parent` (both refer to the root) and `outer_expn`, I cannot find the specific connection between them. Therefore, I chose a solution that may not be the best: give up the incremental compile cache to ensure we can use `span_a` in this case.

r?  ``@petrochenkov`` Do you have any advice on this? Or perhaps this solution is acceptable?

Enable `f16` on x86 and x86-64

Since the `compiler_builtins` update [1], ABI bugs on x86 should be resolved. Enable tests for f16 on these platforms now.

[1]: rust-lang#125016

try-job: i686-gnu
try-job: dist-i586-gnu-i586-i686-musl

…it_unsafe, r=tgross35

WASI: forbid `unsafe_op_in_unsafe_fn` for `std::{os, sys}`

Part of rust-lang#127747 for WASI

try-job: test-various

…ints, r=davidtwco

 Improve diagnostic-related lints: `untranslatable_diagnostic` & `diagnostic_outside_of_impl`

Summary:
- Made `untranslatable_diagnostic` point to problematic arguments instead of the function call
  (I found this misleading while working on some `A-translation` PRs: my first impression was that
  the methods themselves were not translation-aware and needed to be changed,
  while in reality the problem was with the hardcoded strings passed as arguments).
- Made the shared pass of `untranslatable_diagnostic` & `diagnostic_outside_of_impl` more efficient.

``@rustbot`` label D-imprecise-spans A-translation

…, r=jieyouxu

Allow rust staticlib to work with MSVC's /WHOLEARCHIVE

This fixes rust-lang#129020 by renaming the `__NULL_IMPORT_DESCRIPTOR` to prevent conflicts.

try-job: dist-i686-msvc

…=light, r=GuillaumeGomez

rustdoc: animate the `:target` highlight

This approach is, roughly, based on how Discourse does it. It came up while discussing [some other possible sidebar changes](https://rust-lang.zulipchat.com/#narrow/stream/266220-t-rustdoc/topic/Moving.20deprecated.20items.20out.20of.20the.20way), as a design that made rapid scanning easier while avoiding the inherent trade-offs in summarizing.

https://github.com/user-attachments/assets/f7a8fec3-70a5-40a1-92ea-bfdffbd61c22

…n_check_language_ub, r=workingjubilee,the8472

Change `assert_unsafe_precondition` docs to refer to `check_language_ub`

…r, r=Noratrieb

Add `const_cell_into_inner` to `OnceCell`

`Cell` and `RefCell` have their `into_inner` methods const unstable. `OnceCell` has the same logic, so add it under the same gate.

Tracking issue: rust-lang#78729

Advise against removing the remaining Python scripts from `tests/run-make`

After some recent PRs (e.g. rust-lang#129185), there are only two Python scripts left in `tests/run-make`.

Having come so far, it's tempting to try to get rid of the remaining ones. But after trying that myself, I've come to the conclusion that it's not worth the extra hassle, especially if it means pulling in an XML-parsing crate just for one test.

This PR therefore leaves behind a few signpost comments to explain why getting rid of these particular scripts has low value.

…-errors

Do not rely on names to find lifetimes.

For some reason, we were trying to find the lifetime parameter from its name, instead of using the def_id we have.

This PR uses it instead. This changes some ui tests, I think to be more sensible.