[llvm] [MachineLICM] Correctly Apply Register Masks (PR #95746)

[Pierre van Houtryve via llvm-commits]

Pierre-vh wrote:

Investigating right now. As it doesn't break any CI I won't revert yet if that's okay. 

I'll revert if some AArch64 maintainer wants me to (@aemerson / @sjoerdmeijer perhaps?) or if I can't tell what the problem is by tomorrow.

https://github.com/llvm/llvm-project/pull/95746