[clang] [flang] [Flang][Driver] NFC: Move Flang/Fortran only options to a separate file (PR #194398)

[Tarun Prabhu via cfe-commits]

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

Thanks for all the changes, Kiran.

https://github.com/llvm/llvm-project/pull/194398