[llvm] [LoopFusion] Fix false-positive dependency blocking fusion of idempot… (PR #206401)

[Ehsan Amiri via llvm-commits]

amehsan wrote:

> Gentle Ping for Review

I have already approved and you can merge. If you don't have commit access I can merge it for you. One approval is enough.

https://github.com/llvm/llvm-project/pull/206401