[clang] [flang] [flang][Driver] Support -fdiagnostics-color (PR #109210)

[Tarun Prabhu via cfe-commits]

tarunprabhu wrote:

Thanks for the review, @MaskRay. @tblah, @kiranchandramohan, does this look ok to you?

https://github.com/llvm/llvm-project/pull/109210