[llvm] [LoopInterchange] Don't rely on ASSERTS build for tests. NFC. (PR #116780)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

Remarks shouldn't require asserts and checking the remark if interchange didn't happen seems like a more straight-forward way then checking the IR in some cases

https://github.com/llvm/llvm-project/pull/116780