Add benchmarks.run_pgo_optrepeat collection

[EgorBo]

It'd be nice to have a collection where we can see impact of JitOptRepeat-specific optimizations

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[EgorBo]

@BruceForstall @jakobbotsch @dotnet/jit-contrib opinions?

[Copilot]

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

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• src/coreclr/scripts/superpmi-collect.proj: Language not supported

[AndyAyersMS]

Would also be nice to fix the benchmarks runs to use a release corelib/coreclr and checked jit.

[jakobbotsch]

If we add it, can we replace one of the existing benchmarks collections with it? E.g. do we really feel like we get any use out of benchmarks.run_tiered?

[BruceForstall]

I like the idea. We can run it and see how it goes.

[EgorBo]

If we add it, can we replace one of the existing benchmarks collections with it? E.g. do we really feel like we get any use out of benchmarks.run_tiered?

Removed.

Will merge the PR on Sunday before we do the scheduled re-collect

[EgorBo]

/ba-g "naot win-x64 job timed out"

[BruceForstall]

btw, this was mentioned as part of #108902