add support for both cuda compatible implementation and hcc(faster)
implementation with test
Change-Id: I79a22344f458391d7dffac5f147619a542e97e4e
[ROCm/hip commit: 8264d5d6bd]
- Add hierarchy. Tests now live in directories, each with its own
CMakeFiles.txt. Reduces merge conflicts.
- Change make_hip_executable -> build_hip_executable.
- Refresh docs.
- Enable some tests that were previously built but not run.
Change-Id: I8c5de3c954400bf233904282b8b42861a2b7c536
[ROCm/hip commit: 1b69b2e9f0]