7e2f1ae7e0
Relative to the previous attempt, this also adjusts RegionInfo verification to allow unreachable predecessors. ----- If a block in the CHR region has an unreachable predecessor, then there will be no edge from that predecessor to the newly cloned block. However, a phi node entry for it will be left behind. Make sure that these incoming blocks get dropped as well. Fixes https://github.com/llvm/llvm-project/issues/64594. Differential Revision: https://reviews.llvm.org/D157621