[clang] [CUDA][HIP] add option -gpuinc (PR #140106)

[Yaxun Liu via cfe-commits]

yxsamliu wrote:

> > but there is other comgr user expecting comgr to have -nogpuinc by default. changing that will cause regressions.
> 
> If `comgr` can have custom flags then you could just pass the 'do not pass `-nogpuinc` by default' flag presumably.

As I said, I think this is just one case that we need an option to override -nogpuinc. changes are we will need it in other situations.

https://github.com/llvm/llvm-project/pull/140106