[llvm-branch-commits] [X86] Finish AMX-RegAlloc Related Pipeline Overrides (PR #234079)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/234079

The modification points are now available so finish up this part of the
pipeline, just matching the behavior from the X86 TargetPassConfig for
the LegacyPM.