[llvm] Revert "[SimplifyCFG] Deduce paths unreachable if they cause div/rem UB" (PR #137741)

[Bill Wendling via llvm-commits]

bwendling wrote:

@nikic and @dtcxzyw, since you both NACK'ed this patch, please offer a way to address this issue rather than using hidden flags. This issue is not simply a Linux kernel issue. It may happen to anyone who uses Clang. So I'd like to know the best way to address this.

https://github.com/llvm/llvm-project/pull/137741