[clang] [flang] [llvm] [openmp] [Flang][OpenMP] Move builtin .mod generation into runtimes (PR #137828)

[David Truby via llvm-commits]

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

This LGTM other than my concerns about the specific CMake version where flang was properly supported. Thanks!

https://github.com/llvm/llvm-project/pull/137828