[llvm] [NVPTX] Do not run the NVVMReflect pass as part of the normal pipeline (PR #121834)

[Artem Belevich via llvm-commits]

Artem-B wrote:

The problem is that libdevice depends on this patch and it does carry a fair amount of code that will no longer benefit from removal of unused conditional branches.
The way libdevice is used in CUDA, the intent was to process conditional bitcode early.
If OpenMP wants to do it differently, I would prefer to make it a special case, and keep the early reflect pass for CUDA.

https://github.com/llvm/llvm-project/pull/121834