[clang] [llvm] [llvm][AArch64] apple-m4 is armv9.2-a (PR #98267)

[Tomas Matheson via llvm-commits]

https://github.com/tmatheson-arm approved this pull request.

LGTM. I haven't checked all the CPU feature changes, but the tests give a lot of confidence. I also haven't checked all the TRMs but the changes there make sense given the MEC/RME architecture changes.

https://github.com/llvm/llvm-project/pull/98267