[flang] [mlir] [clang] [Flang][OpenMP][MLIR] Add support for -nogpulib option (PR #71045)

[via cfe-commits]

agozillon wrote:

It would be very nice to have this option added to Flang in the near future, as this option would allow the OpenMP libomptarget runtime tests for offload to be ran without failure due to this missing option. I believe we are currently in the process of setting up a buildbot that includes these tests, it's not a blocker for the buildbot from what I understand, but it'd be very nice to be able to test for success of these tests on commits in the near future, especially as the suite expands.  

https://github.com/llvm/llvm-project/pull/71045