[llvm] [ConstraintElim] Support adding facts from switch terminators. (PR #67061)

[Nikita Popov via llvm-commits]

https://github.com/nikic approved this pull request.

LGTM, but can you please also add a negative test with a multi-edge from the switch? I.e. two cases going to the same block. I think the dominates query handles this correctly, but better be sure.

https://github.com/llvm/llvm-project/pull/67061