Adding support for X86Base.Pause() and ArmBase.Yield()

[tannergooding]

This resolves#53532

[ghost]

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Issue Details

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This resolves #53532

Author:	tannergooding
Assignees:	-
Labels:	area-CodeGen-coreclr, new-api-needs-documentation
Milestone:	-

[EgorBo]

it's 14x lower on pre-Skylakes. It reminds me this issue #8744

[tannergooding]

Yes, but all of our latencies are currently dependent on and configured for Skylake.

We'd need some more advanced setup if we wanted to track per architecture latencies/throughput.

[echesakov]

I assume this is no-diff change?

[tannergooding]

I assume this is no-diff change?

Correct, although it looks like there is some minor issue on Arm64 I might need to fix still.

[tannergooding]

@echesakovMSFT, could you take a quick peak at the one additional commit that resolves the ARM64 issue.

It's now generating the correct code and working as expected. The issue was that the category wasn't being handled correctly and a few tweaks were needed to handle there being no args, no base type, and no EA_ATTR.

[echesakov]

The last change LGTM.