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.
All checks should not occur in input file for FileCheck. The issue found on CHECK-NOT.
Change removes all lit checks in the hipified file based on regexp, and the resulted stdout is fed as stdin for FileCheck.