[flang] [clang] [Flang][Driver] Enable gpulibc/nogpulibc options for Flang, which allows linking of GPU LIBC for the fortran and OpenMP runtime (PR #77135)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> Makes sense to me, though this is not my area of expertise. Could you add a bit more elaborate test? Perhaps something that would check the linker invocation>?

I'm not familiar with how Fortran handles stuff here. It's tested in the `clang` portion at least. The handling of this is in `CommonArgs` somewhere I believe. If Fortran shares that it should be inherited, so it's at least tested in the `clang` version so it might be fine.

https://github.com/llvm/llvm-project/pull/77135