[llvm] [InstCombine] Rewrite multi-use GEPs when simplifying comparison (PR #146100)

[Nikita Popov via llvm-commits]

nikic wrote:

This has an interesting impact on clang stage2: https://llvm-compile-time-tracker.com/compare.php?from=c503c5e26baf942773379e1b445e6730066005a9&to=a9122c1e6a652860a7636e15ae5e227538161f47&stat=instructions:u Most likely perturbing an inlining heuristic in a way that happens to be favorable.

https://github.com/llvm/llvm-project/pull/146100