[llvm] [DebugInfo][RemoveDIs] Make debugify pass convert to/from RemoveDIs mode (PR #73251)

[Orlando Cazalet-Hyams via llvm-commits]

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

LGTM other than a quibble about the variable name

https://github.com/llvm/llvm-project/pull/73251