[flang-commits] [flang] [flang][OpenMP] Switch SOURCE/SINK to use modifier infrastructure (PR #217644)

[Caroline Newcombe via flang-commits]

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

LGTM with minor comments. This would benefit from a second review (I am still new to reviewing OpenMP).

https://github.com/llvm/llvm-project/pull/217644