SWDEV-460770 - Handle Graph Exec release

Handle GraphExec instance is destroyed before async launch completes
GraphExec instance is destroyed after async launch completes
GraphExec instance is destroyed without a launch

Change-Id: I45a7c82295fea916c7559bd8f796df710513aea1

hipamd/src/hip_event.cpp

@@ -444,7 +444,8 @@ hipError_t hipEventSynchronize(hipEvent_t event) {
   hipError_t status = e->synchronize();
   // Release freed memory for all memory pools on the device
   g_devices[e->deviceId()]->ReleaseFreedMemory();
-
+  // Release all graph exec objects destroyed by user.
+  ReleaseGraphExec(e->deviceId());
   HIP_RETURN(status);
 }