Convert JIT/Performance to a merged test group

[markples]

See https://github.com/markples/utils/tree/for-PR-dotnet-runtime-85847-others for ILTransform tool. As usual, I recommend viewing the commit list since it partitions the changes in a more readable way and paying more attention to manual changes.

• Does anything special need to be done for this directory?
• outerloop, extra-platforms, gcstress

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Issue Details

---

See https://github.com/markples/utils/tree/for-PR-dotnet-runtime-85847-others for ILTransform tool. As usual, I recommend viewing the commit list since it partitions the changes in a more readable way.

Author:	markples
Assignees:	markples
Labels:	test-enhancement, area-CodeGen-coreclr
Milestone:	-

[markples]

/azp run runtime-coreclr outerloop, runtime-extra-platforms, runtime-coreclr gcstress0x3-gcstress0xc

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[markples]

This is ready @trylek @dotnet/jit-contrib with the question of whether anything special needs to be done for these performance tests (which seem to be a mirror of the actual performance tests used for correctness testing).

[trylek]

Looks great to me but I must admit I don't have too much of a context on the perf side of these tests.

[BruceForstall]

It's useful to keep these tests' source code as close to equivalent to the dotnet/performance repo versions as possible -- at least in the core algorithm part.

[markples]

Thank you for all of the quick reviews @trylek!

[markples]

@BruceForstall Thanks for the comment. These diffs are at the "Main" level, not in the core code. I tried to diff the directories, and that part is already different ([Benchmark] vs not) as well as typo fixes, etc., so I think that this is fine.