In rust-lang#124748, I mistakenly conflated
"not SjLj" to mean "ARM EHABI", which isn't true, watchOS armv7k
(specifically only that architecture) uses a third unwinding method
called "DWARF CFI".

- remove an outdated FIXME
- add reference to floating-point semantics issue

Co-authored-by: Jubilee <workingjubilee@gmail.com>

This is needed for Clippy to know that the `#[allow(unused)]` attributes
added by the expansion of `?` are part of the desugaring, and that they
do not come from the user code.

rust-lang/rust-clippy#13380 exhibits a manifestation of this problem.

It seems QNX 7.0 does not support `linkat` at all (most tests were failing). Limiting to QNX 7.0 only, while using `linkat` for the future versions seems like the right path forward (tested on 7.0).

Fixes 129895

…ble, r=compiler-errors

Don't warn empty branches unreachable for now

The [stabilization](rust-lang#122792) of `min_exhaustive_patterns` updated the `unreachable_pattern` lint to trigger on empty arms too. This has caused some amount of churn, and imposes an unjoyful `#[allow(unreachable_patterns)]` onto library authors who want to stay backwards-compatible.

While I think the lint should eventually cover these cases, for transition's sake I'd prefer to revert linting to what it was prior to stabilization, at least for now.

Fixes rust-lang#129031.

r? ``@compiler-errors``

update stdarch

The goal is mostly to pull in rust-lang/stdarch#1633.

r? ```@Amanieu```

…ilee

enable const-float-classify test, and test_next_up/down on 32bit x86

The  test_next_up/down tests have been disabled on all 32bit x86 targets, which goes too far -- they should definitely work on our (tier 1) i686 target, it is only without SSE that we might run into trouble due to rust-lang#114479. However, I cannot reproduce that trouble any more -- maybe that got fixed by rust-lang#123351?

The  const-float-classify test relied on const traits "because we can", and got disabled when const traits got removed. That's an unfortunate reduction in test coverage of our float functionality, so let's restore the test in a way that does not rely on const traits.

The const-float tests are actually testing runtime behavior as well, and I don't think that runtime behavior is covered anywhere else. Probably they shouldn't be called "const-float", but we don't have a `tests/ui/float` folder... should I create one and move them there? Are there any other ui tests that should be moved there?

I also removed some FIXME referring to not use x87 for Rust-to-Rust-calls -- that has happened in rust-lang#123351 so this got fixed indeed. Does that mean we can simplify all that float code again? I am not sure how to test it. Is running the test suite with an i586 target enough?

Cc ```@tgross35``` ```@workingjubilee```

…ingjubilee

Fix linking error when compiling for 32-bit watchOS

In rust-lang#124494 (or rust-lang#124748), I mistakenly conflated "not SjLj" to mean "ARM EHABI", which isn't true, 32-bit watchOS uses a third unwinding method called "DWARF CFI".

So this PR is effectively a revert of rust-lang#124494, with a few more comments explaining what's going on.

Fixes rust-lang#130071.

r? Mark-Simulacrum (since you reviewed the original)

…iler-errors

Remove needless returns detected by clippy in the compiler

…links, r=ChrisDenton

maint: update docs for change_time ext and doc links

maint: update docs for change_time ext and doc links

Related: rust-lang#121478
r? tgross35

…hlin

notify Miri when intrinsics are changed

`@rust-lang/miri` should we notify the entire team, or should I just add myself?

… r=compiler-errors

miri: fix overflow detection for unsigned pointer offset

This is the Miri part of rust-lang#130229. This is already UB in codegen so we better make Miri detect it; updating the docs may take time if we have to follow some approval process, but let's make Miri match reality ASAP.

r? ``@scottmcm``

…-fix, r=jieyouxu

Use the same span for attributes and Try expansion of ?

This is needed for Clippy to know that the `#[allow(unused)]` attributes added by the expansion of `?` are part of the desugaring, and that they do not come from the user code.

rust-lang/rust-clippy#13380 exhibits a manifestation of this problem and will be fixed by this change.

Limit `libc::link` usage to `nto70` target only, not NTO OS

It seems QNX 7.0 does not support `linkat` at all (most tests were failing). Limiting to QNX 7.0 only, while using `linkat` for the future versions seems like the right path forward (tested on 7.0).

Fixes rust-lang#129895

CC: `@japaric` `@flba-eb` `@saethlin`