[llvm] [LoopInterchange] Prevent the transformation stage from stopping partway (PR #205564)

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llvmbot wrote:

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>/cherry-pick https://github.com/llvm/llvm-project/commit/ca52c1b3abbadf829598872b7dded2bca2fd50c0

Error: Command failed due to missing milestone.

https://github.com/llvm/llvm-project/pull/205564