Update stdarch submodule

[GuillaumeGomez]

rust-lang/stdarch#1768 is needed to unblock the cg_gcc current sync so this PR updates the stdarch submodule.

cc @antoyo
r? @Amanieu

[rustbot]

⚠️ Warning ⚠️

• Some commits in this PR modify submodules.

[Amanieu]

@bors r+ rollup=never

[bors]

📌 Commit 299877e has been approved by Amanieu

It is now in the queue for this repository.

[bors]

⌛ Testing commit 299877e with merge c6aad02...

[bors]

☀️ Test successful - checks-actions
Approved by: Amanieu
Pushing c6aad02 to master...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing afa859f (parent) -> c6aad02 (this PR)

Test differences

Show 24 test diffs

24 doctest diffs were found. These are ignored, as they are noisy.

Job duration changes

1. x86_64-apple-2: 3877.1s -> 5278.7s (36.2%)
2. dist-x86_64-apple: 8731.8s -> 11736.4s (34.4%)
3. i686-gnu-2: 6430.8s -> 7433.9s (15.6%)
4. dist-apple-various: 8218.1s -> 6956.0s (-15.4%)
5. dist-aarch64-linux: 5229.5s -> 5693.8s (8.9%)
6. x86_64-mingw-1: 8604.7s -> 9366.5s (8.9%)
7. dist-s390x-linux: 5181.7s -> 5583.9s (7.8%)
8. x86_64-gnu-llvm-20-2: 5843.9s -> 6253.3s (7.0%)
9. x86_64-gnu-distcheck: 4769.6s -> 4467.3s (-6.3%)
10. aarch64-apple: 3899.0s -> 4134.1s (6.0%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (c6aad02): 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 (primary -0.5%, secondary -0.1%)

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)	0.7%	[0.5%, 0.9%]	3
Regressions ❌ (secondary)	3.2%	[1.8%, 4.7%]	2
Improvements ✅ (primary)	-0.9%	[-2.1%, -0.4%]	9
Improvements ✅ (secondary)	-2.3%	[-2.6%, -1.9%]	3
All ❌✅ (primary)	-0.5%	[-2.1%, 0.9%]	12

Cycles

Results (primary 0.3%, secondary 2.4%)

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)	0.6%	[0.4%, 0.9%]	9
Regressions ❌ (secondary)	2.4%	[2.4%, 2.4%]	1
Improvements ✅ (primary)	-0.5%	[-0.6%, -0.4%]	3
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[-0.6%, 0.9%]	12

Binary size

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

Bootstrap: 776.859s -> 775.438s (-0.18%)
Artifact size: 364.72 MiB -> 364.76 MiB (0.01%)