[llvm] Reapply "[CodeGen] Remove `applySplitCriticalEdges` in `MachineDominatorTree` (#97055)" (PR #98446)

[via llvm-commits]

paperchalice wrote:

Use strategy eager in `MachineLICM`, because dominator tree is used immediately after updating. Flush updater after all critical edges are split in `MachineSink`.
If the performance is still unacceptable, I will make another PR to wrap machine dominator tree, the name `getBase()` doesn't make sense...
  

https://github.com/llvm/llvm-project/pull/98446