[llvm] [MachineLICM] Work-around Incomplete RegUnits (PR #95926)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

Thanks; with this fix merged now, my original case (as explained in https://github.com/llvm/llvm-project/pull/95746#issuecomment-2175591938) works correctly again.

https://github.com/llvm/llvm-project/pull/95926