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

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

Ok, here goes: 
[before-after.zip](https://github.com/user-attachments/files/15883954/before-after.zip)

`before.mir` from the output of `-stop-before=machinelicm`, and `after-good.mir` and `after-bad.mir` from `-stop-after=machinelicm`. The diff between the two after cases is pretty small and I can't say for certain whether it's faulty or not, hopefully you can.

Otherwise I'm afraid that this actually would be a lingering aarch64 target bug that just happens to appear due to this, otherwise potentially valid, change. For that, we'd have to invoke some aarch64 target maintainer...

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