[llvm] [InstCombine] Simplify the pointer operand of store if writing to null is UB (PR #127979)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

>From a quick `git grep "getCalledFunction()->getName()"`, it looks like there are a lot more places that could use this.

https://github.com/llvm/llvm-project/pull/127979