[llvm] [Frontend][OpenMP] Apply ompx_attribute to all allowing leaf constructs (PR #100370)

[Johannes Doerfert via llvm-commits]

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

Likely this is the best option. In practice, we used it so far only to attach it to the outermost directive (target) but it should never be a bad idea to attach it to all.

https://github.com/llvm/llvm-project/pull/100370