hipStreamSynchronize can skip marker if stream is empty (#1667)

src/hip_hcc.cpp

@@ -310,6 +310,8 @@ void ihipStream_t::locked_wait() {
     hc::completion_future marker;
     {
         LockedAccessor_StreamCrit_t crit(_criticalData);
+        // skipping marker since stream is empty
+        if (crit->_av.get_is_empty()) return;
         marker = crit->_av.create_marker(hc::no_scope);
     }