[llvm] [IsolatePath] Add a pass to isolate paths with undefined behavior (PR #146791)

[Nikita Popov via llvm-commits]

nikic wrote:

I fundamentally disagree with what this is trying to do. *I* want paths that always lead to UB to be eliminated. Both as a user of C/C++, but especially as a user of memory safe languages.

I *might* accept this as an optional hardening mode, but I don't think this has any business being part of the default pipeline.

(My previous guidance to expose trap-unreachable in clang and enable it by default stands.)

https://github.com/llvm/llvm-project/pull/146791