[llvm] [IR] Change PHINode::removeIncomingValueIf() to loop incoming values backwards (PR #173444)

[Mingjie Xu via llvm-commits]

Enna1 wrote:

Except LoopSimplify and LoopUtils, all other uses of `PHINode::removeIncomingValueIf()` use incoming block based predicate.


https://github.com/llvm/llvm-project/pull/173444