[llvm] [BranchFolding] Fix missing predecessors of landing-pad (PR #77608)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

> This keeps CFG as only have one entry which is required by LiveDebugValues

If we just want to make LiveDebugValues happy, should it better to remove these died BB instead?


https://github.com/llvm/llvm-project/pull/77608