[llvm] [LoopUnroll] Penalize interior control flow (PR #67137)

[David Green via llvm-commits]

davemgreen wrote:

I think this would be OK for the original case in x264 that was worse, and sounds like it would make sense in general. I'm not sure about other specific cases though, I know of cases where the outer loop unrolling can help the inner loop unroll too. Like in the example in https://reviews.llvm.org/D156532#4574569 but with more inner loops.

https://github.com/llvm/llvm-project/pull/67137