[HIPIFY] Fix warnings on unhandled refs.
[HIPIFY] Fix warnings on unhandled refs.

CUstream_st -> hipStream_t *
CUevent_st -> hipEvent_t * (fixed, was -> hipEvent_t)

Warning:
[HIPIFY] warning: the following reference is not handled: 'CUstream_st' [struct var ptr]. (thrust/examples/cuda/async_reduce.cu)

GPUOpen-ProfessionalCompute-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,ROCm-Developer-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP