Update stdarch

[jhpratt]

library/stdarch bcbe010...d215afe (7):

• Add the rdm target feature to the sqrdmlsh intrinsic. (Add the rdm target feature to the sqrdmlsh intrinsic. stdarch#1285)
• Remove use of #[rustc_deprecated]
• Remove feature gates for stabilized features
• Change remaining undefined functions to zero-init
• Use SPDX license format and update packed_simd crate link (Use SPDX license format and update packed_simd crate link stdarch#1297)
• Fix broken links (Fix broken links stdarch#1294)
• Import the asm macro in std_detect (Import the asm macro in std_detect stdarch#1290)

[rust-highfive]

Thank you for submitting a new PR for the library teams! If this PR contains a stabilization of a library feature that has not already completed FCP in its tracking issue, introduces new or changes existing unstable library APIs, or changes our public documentation in ways that create new stability guarantees then please comment with r? rust-lang/libs-api @rustbot label +T-libs-api to request review from a libs-api team reviewer. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary

[rust-highfive]

r? @kennytm

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[rust-highfive]

⚠️ Warning ⚠️

• These commits modify submodules.

[Dylan-DPC]

@bors r+ rollup=never

[bors]

📌 Commit 2638e96 has been approved by Dylan-DPC

[bors]

⌛ Testing commit 2638e96 with merge dc4bfcb...

[bors]

☀️ Test successful - checks-actions
Approved by: Dylan-DPC
Pushing dc4bfcb to master...

[rust-timer]

Finished benchmarking commit (dc4bfcb): comparison url.

Summary:

• Primary benchmarks: 😿 relevant regression found
• Secondary benchmarks: 😿 relevant regressions found

	Regressions 😿 (primary)	Regressions 😿 (secondary)	Improvements 🎉 (primary)	Improvements 🎉 (secondary)	All 😿 🎉 (primary)
count1	1	8	0	0	1
mean2	1.1%	0.7%	N/A	N/A	1.1%
max	1.1%	1.2%	N/A	N/A	1.1%

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression

Footnotes

1. number of relevant changes ↩

2. the arithmetic mean of the percent change ↩

[pnkfelix]

Visiting for weekly performance triage.

This causes a 1.11% performance regression on a single primary benchmark, namely unicode-normalization-0.1.19 debug full.

I am vaguely curious what the root cause might be. Not sure how much time I want to invest in finding out, but I will hold off on marking this as triaged until later this evening when I might have chance to look at some cachegrind output or something. (Currently my best guess is it might have something to do with the switch from the "change remaining undefined functions to zero-init" in the changes listed in the description.)

[pnkfelix]

I have done a number of local cachegrind runs to try to evaluate the root cause, and so far my main finding is that I'm seeing a lot of noise in the data this yields. The total number of instruction counts is on the order of 4,182M +/- 1M., but the point is that sometimes the cachegrind diff says that the results went down by 1.4M, and other times it says it went up by 3M.

Overall it seems like the regression being flagged here may be in the noise overall.

@rustbot label: +perf-regression-triaged