Fix hipmemset to match CUDA behavior
Fix hipmemset to match CUDA behavior

Make hipMemset asynchronous with respect to the host unless
destination pointer refers to pinned host memory.

Change-Id: I5ba230e0cc622aa076dc94692a4c43a57dd2df7b

ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP