[llvm] [CodeGenPrepare] Bail out of usubo creation if sub's parent is not the same as the comparison (PR #160358)

[via llvm-commits]

AZero13 wrote:

@arsenm I don't want to put the cart before the horse. I have another PR dedicated to that with its own new matcher. 

https://github.com/llvm/llvm-project/pull/160358