[llvm] [IfConversion] Preserve debug info when flipping a branch (PR #114614)

[Ellis Hoag via llvm-commits]

ellishg wrote:

I can't find a test case where the debug location was incorrect or missing before this change, but it is fairly easy to find a test that executes this code (some existing tests already do). Is this acceptable to land without a test?

https://github.com/llvm/llvm-project/pull/114614