[REASON]
1. hip-clang is fine with the templated kernel launch, brackets are unneeded: HIP_KERNEL_NAME(...) __VA_ARGS__
2. HCC is not, thus: HIP_KERNEL_NAME(...) (__VA_ARGS__)
[TODO] Clean-up entirely kernel name wrapping when HCC is finally obsolete.
+ Update perl generation, hipify-perl, and affected tests accordingly.
Repeats clang's '--cuda-path' option.
[Reason]
In case of absence of any other clang's options setting '-cuda-path' allows not to specify separator '--' before clang's '--cuda-path'.
+ Tests and scripts are updated accordingly.