[llvm] [AA] Make alias check more accurately. (PR #137747)

[Nikita Popov via llvm-commits]

https://github.com/nikic requested changes to this pull request.

The roughly 1k test failures are a big clue that this change is incorrect. This completely breaks composability of different AA providers.

It sounds to me like you are trying to work around UB in the source problem. Use `-fno-strict-aliasing` if you want to opt out of strict aliasing requirements.

https://github.com/llvm/llvm-project/pull/137747