llvm-project

1562b70e - Reapply "[DomTreeUpdater] Move critical edge splitting code to updater" (#119547)

Reapply "[DomTreeUpdater] Move critical edge splitting code to updater" (#119547) This relands commit #115111. Use traditional way to update post dominator tree, i.e. break critical edge splitting into insert, insert, delete sequence. When splitting critical edges, the post dominator tree may change its root node, and `setNewRoot` only works in normal dominator tree... See https://github.com/llvm/llvm-project/blob/6c7e5827eda26990e872eb7c3f0d7866ee3c3171/llvm/include/llvm/Support/GenericDomTree.h#L684-L687