Added new API, hipMemPtrGetInfo

1. This API returns memory allocation size of pointer
2. Added test to check its functionality

Change-Id: I87976d817b5a6ca5530336c09e7cb0420601cb2c

include/hip/hcc_detail/hip_runtime_api.h

@@ -1236,6 +1236,9 @@ hipError_t hipMemsetAsync(void* dst, int value, size_t sizeBytes, hipStream_t st
 hipError_t hipMemGetInfo  (size_t * free, size_t * total)   ;
 
 
+hipError_t hipMemPtrGetInfo(void *ptr, size_t *size);
+
+
 /**
  *  @brief Allocate an array on the device.
  *