[llvm] [LoopUnroll] Rotate loop before unrolling inside of UnrollRuntimeLoopRemainder (PR #148243)

[Marek Sedláček via llvm-commits]

mark-sed wrote:

@annamthomas Good suggestions. I have now added an argument to `UnrollRuntimeLoopRemainder`, which allows to rotate the loop and disabled it for UnrollAndJam. I'll now add the other part, which is a detection if unroll worked without rotation and if not, I'll also rotate the loop.

https://github.com/llvm/llvm-project/pull/148243