Add support for Arm64EC to the Standard Library

[dpaoliello]

Adds the final pieces so that the standard library can be built for arm64ec-pc-windows-msvc (initially added in #119199)

• Bumps windows-sys to 0.56.0, which adds support for Arm64EC.
• Correctly set the isEC parameter for LLVM's writeArchive function.
• Add #![feature(asm_experimental_arch)] to library crates where Arm64EC inline assembly is used, as it is currently unstable.

[rustbot]

r? @GuillaumeGomez

rustbot has assigned @GuillaumeGomez.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[workingjubilee]

...I'm confused why such a pervasive library change assigned someone from docs? Rustbot? You okay over there?

[dpaoliello]

...I'm confused why such a pervasive library change assigned someone from docs? Rustbot? You okay over there?

I did change some docs, so 🤷

[GuillaumeGomez]

Apart from my nits, docs changes look good. 😉

However, please assign someone else for the final approval.

[dpaoliello]

r? libs

[ChrisDenton]

windows_sys.rs is a generated file so any manual changes will be overwritten. See https://github.com/rust-lang/rust/blob/master/library/std/src/sys/pal/windows/c/README.md

You can override definitions by putting them in library/std/src/sys/pal/windows/c.rs but ideally fixes should be done in windows-bindgen (well, more likely the win32metadata project from which bindings are derived).

[dpaoliello]

windows_sys.rs is a generated file so any manual changes will be overwritten. See https://github.com/rust-lang/rust/blob/master/library/std/src/sys/pal/windows/c/README.md

You can override definitions by putting them in library/std/src/sys/pal/windows/c.rs but ideally fixes should be done in windows-bindgen (well, more likely the win32metadata project from which bindings are derived).

Submitted a PR to add Arm64EC support in windows-rs: microsoft/windows-rs#2957

[dpaoliello]

@rustbot blocked

Need to update windows-rs

[rustbot]

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

Some changes occurred in src/doc/rustc/src/platform-support

cc @Nilstrieb

[dpaoliello]

windows-sys 0.56 has support for Arm64EC, so this PR is ready to go
@rustbot ready

[ChrisDenton]

The libs changes look good to me, though I've not tested it.

[dpaoliello]

The libs changes look good to me, though I've not tested it.

Thanks!

Sounds like the only piece left to review is the compiler changes.
r? compiler

[wesleywiser]

Compiler changes look good to me

[wesleywiser]

@bors r=GuillaumeGomez,ChrisDenton,wesleywiser

[bors]

📌 Commit 32f5ca4 has been approved by GuillaumeGomez,ChrisDenton,wesleywiser

It is now in the queue for this repository.

[bors]

⌛ Testing commit 32f5ca4 with merge c5de414...

[bors]

☀️ Test successful - checks-actions
Approved by: GuillaumeGomez,ChrisDenton,wesleywiser
Pushing c5de414 to master...

[rust-timer]

Finished benchmarking commit (c5de414): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.1%	[-2.1%, -2.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.1%	[-2.1%, -2.1%]	1

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 676.875s -> 677.567s (0.10%)
Artifact size: 315.38 MiB -> 315.40 MiB (0.00%)