r352221 caused regressions in CUDA/HIP since device function may use _Float16 whereas host does not support it.
In this case host compilation should not diagnose usage of _Float16 in device functions or variables.
For now just do not diagnose _Float16 for CUDA/HIP. In the future we should have more precise check.
Differential Revision: https://reviews.llvm.org/D57369
llvm-svn: 352488
Yaxun Liu