[llvm] [DLCov][NFC] Propagate annotated DebugLocs through transformations (PR #138047)

[Orlando Cazalet-Hyams via llvm-commits]

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

One final inline comment which I think would help reduce my fears of introducing a similar/same name function that differs slightly.

https://github.com/llvm/llvm-project/pull/138047