Add event controls for release fences.

Env var : HIP_EVENT_SYS_RELEASE
Event allocation flags : hipEventReleaseToDevice, hipEventReleaseToSystem
   (remove hipEventDisableSystemRelease)

Update test for new functionality.

hipamd/include/hip/hcc_detail/hip_runtime_api.h

@@ -106,7 +106,8 @@ enum hipLimit_t
 #define hipEventBlockingSync        0x1  ///< Waiting will yield CPU.  Power-friendly and usage-friendly but may increase latency.
 #define hipEventDisableTiming       0x2  ///< Disable event's capability to record timing information.  May improve performance.
 #define hipEventInterprocess        0x4  ///< Event can support IPC.  @warning - not supported in HIP.
-#define hipEventDisableSystemRelease 0x80000000  /// < Disable the system-scope release that event normally performs when it records.  This flag is useful to obtain more precise timings of commands between events.  The flag is a no-op on CUDA platforms.
+#define hipEventReleaseToDevice     0x40000000  /// < Use a device-scope release when recording this event.  This flag is useful to obtain more precise timings of commands between events.  The flag is a no-op on CUDA platforms.
+#define hipEventReleaseToSystem     0x80000000  /// < Use a system-scope release that when recording this event.  This flag is useful to make non-coherent host memory visible to the host.  The flag is a no-op on CUDA platforms.
 
 
 //! Flags that can be used with hipHostMalloc

hipamd/include/hip/nvcc_detail/hip_runtime_api.h

@@ -58,7 +58,8 @@ hipMemcpyHostToHost
 #define hipEventBlockingSync         cudaEventBlockingSync
 #define hipEventDisableTiming        cudaEventDisableTiming
 #define hipEventInterprocess         cudaEventInterprocess
-#define hipEventDisableSystemRelease cudaEventDefault  /* no-op on CUDA platform */
+#define hipEventReleaseToDevice      0  /* no-op on CUDA platform */
+#define hipEventReleaseToSystem      0  /* no-op on CUDA platform */
 
 
 #define hipHostMallocDefault       cudaHostAllocDefault