[clang] [flang] [Flang-new][OpenMP] Add bitcode files for AMD GPU OpenMP (PR #96742)

[Andrzej Warzyński via cfe-commits]

banach-space wrote:

> > > > Who could be the right person to ask?
> > > 
> > > 
> > > I don't know. Open-source LLVM Flang meetings can be good place to ask this question.
> > 
> > 
> > Did you ask? What feedback did you get?
> 
> @banach-space I asked question on flang-slack, I mentioned the issue on the latest Flang technical meeting and I described potential solution here: https://discourse.llvm.org/t/offloading-on-nvptx64-target-with-flang-new-leads-to-undefined-reference-s/80237 . I got no feedback.
> 
> Can I merge this PR? The issue with -`fcuda-is-device` is resolved. If you wish I can extend driver checks for `-mlink-builtin-bitcode` as a separate PR.

Thanks for following-up! Overall this looks good to me, but please update the summary with some details/context, e.g.
* why are you adding `-nogpulib` in tests?
* "Flang-new needs to add mlink-builtin-bitcode" - please add a note explaining that this flag is added by `addClangTargetOptions()` (that wasn't obvious to me).

Approving as is, no need to wait for me to take another look.

https://github.com/llvm/llvm-project/pull/96742