Update LLVM submodule

[mk12]

This merges upstream release/13.x changes to our fork. In particular,
this includes the bugfix https://reviews.llvm.org/D108608 (see also
https://bugs.llvm.org/show_bug.cgi?id=51637).

The motivation for this is fixing Rust coverage in Fuchsia: https://fxbug.dev/77427.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @cuviper (or someone else) soon.

Please see the contribution instructions for more information.

[rust-highfive]

⚠️ Warning ⚠️

• These commits modify submodules.

[cuviper]

@bors r+

[bors]

📌 Commit ae606a3185f82fb93c0856f2bd8343749c2075bc has been approved by cuviper

[nikic]

I've updated the submodule to a slightly newer merge, as some fixes relevant for us have landed upstream in the meantime, in particular the one for #88769.

@bors r=cuviper rollup=never

[bors]

📌 Commit 8bfd872 has been approved by cuviper

[bors]

⌛ Testing commit 8bfd872 with merge 9748abc1c517202f0e36ef73b90f400b0c93b6c5...

[bors]

💥 Test timed out

[rust-log-analyzer]

A job failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[nikic]

@bors retry timeout

[bors]

⌛ Testing commit 8bfd872 with merge 0212c70...

[bors]

☀️ Test successful - checks-actions
Approved by: cuviper
Pushing 0212c70 to master...

[rust-timer]

Finished benchmarking commit (0212c70): comparison url.

Summary: This change led to moderate relevant mixed results 🤷 in compiler performance.

• Moderate improvement in instruction counts (up to -0.7% on full builds of ctfe-stress-4)
• Moderate regression in instruction counts (up to 0.7% on incr-unchanged builds of ripgrep)

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

[Mark-Simulacrum]

@rustbot label: +perf-regression-triaged

This is necessary for us to keep up to date with upstream LLVM, and the changes here do not seem to merit deep investigation given their magnitude and relative scattering across positive/negative changes.