[llvm] [SimplifyCFG] Deduce paths unreachable if they cause div/rem UB (PR #109008)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

I think the division by zero part of this is reasonable, but handling SignedMin / -1 is an unnecessary complication, especially as it adds another constant root. It's not like `SignedMin / x` is common code.

https://github.com/llvm/llvm-project/pull/109008