Updating xarch to utilize EVEX compares and blending where profitable

[tannergooding]

This updates the xarch intrinsic logic to always import nodes as TYP_MASK where supported and to lower them back to the non-mask variants if no other optimizations were allowed to kick-in. This allows better overall use of the hardware for existing intrinsic code paths.

[dotnet-policy-service]

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[tannergooding]

CC. @dotnet/jit-contrib. This should be ready for review. I could split this up into 2 PRs ([Allow rewriting of hwintrinsic mask ops to their non-mask forms and [Default to using mask ops for V128/V256 on supporting hardware), but I think it's worth doing these two together.

This is one of the last major milestones for the embedded masking support and helps ensure that all vector sizes are getting the expected implicit lightup.

[tannergooding]

The size regressions that are showing are primarily from cases where we decide to fallback to the non-kmask variant and it is comparing against zero. Such cases are now having to emit an extra vxorps since it isn't CSE'd.

In other words, the few regressions are namely due to #70182. We might be able to mitigate some of that by finding an existing CSE with a good VN in range or doing some other backtrack searching tricks, like we've done as workarounds for the issue; but I don't think we should block this PR on that; particularly since many important cases are improved and the vxorps are elided by the register renamer since its just producing 0.

[tannergooding]

/azp run runtime-coreclr jitstress-isas-x86, Fuzzlyn, Antigen, runtime-coreclr jitstress, runtime-coreclr jitstressregs

[azure-pipelines]

Azure Pipelines successfully started running 5 pipeline(s).

[tannergooding]

/azp run runtime-coreclr jitstress-isas-x86, Fuzzlyn, Antigen, runtime-coreclr jitstress, runtime-coreclr jitstressregs

[azure-pipelines]

Azure Pipelines successfully started running 5 pipeline(s).

[tannergooding]

/azp run runtime-coreclr jitstress-isas-x86, Fuzzlyn, Antigen, runtime-coreclr jitstress, runtime-coreclr jitstressregs

[azure-pipelines]

Azure Pipelines successfully started running 5 pipeline(s).