[llvm] [BranchFolding] Kill common hoisted debug instructions (PR #140091)

[Orlando Cazalet-Hyams via llvm-commits]

OCHyams wrote:

Review for adjusted patch in https://github.com/llvm/llvm-project/pull/149999. It'd be nice if I could just re-open this pull request, but either that's not possible or I've just failed to navigate the UI properly

https://github.com/llvm/llvm-project/pull/140091