[llvm] [LV] Fold middle-block branch in post-dissolution removeBranchOnConst. (PR #204243)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

After thinking some more about the patch, I think it would probably be simpler overall to take another separate step first and model the full skeleton in the epilogue plan: https://github.com/llvm/llvm-project/pull/215899.

This + a few other changes should avoid most of the IR-based patching up needed in this patch



https://github.com/llvm/llvm-project/pull/204243