[llvm] [InstCombine] Check nowrap flags when folding comparison of GEPs with the same base pointer (PR #121892)

[Nikita Popov via llvm-commits]

nikic wrote:

> > Reverse ping :)
> 
> Is it necessary to merge this PR now? I was previously planning to merge it after fixing the regression.

As it fixes a miscompile and the regression doesn't seem particularly significant, I think it's better to merge it earlier than later.

https://github.com/llvm/llvm-project/pull/121892