[llvm] [VectorCombine] Fix rotation in phi narrowing. (PR #160465)

[via llvm-commits]

llvmbot wrote:

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Failed to cherry-pick: 8df643f66374fc3fc16523a2d6a63d14d4a560a5

https://github.com/llvm/llvm-project/actions/runs/18096921518

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/160465