Use memset for initializing variable sized array

In ASAN builds, the compiler used is clang. The initialization of
variable sized array using assignment operator is causing compilation
failure in ASAN builds. Used memset to fix the same.

Change-Id: Ifc748291a41a9886243e0fb1ba576d2760f5e15e

runtime/hsa-runtime/core/runtime/signal.cpp

@@ -231,7 +231,8 @@ uint32_t Signal::WaitAny(uint32_t signal_count, const hsa_signal_t* hsa_signals,
     if (signal_count > small_size) delete[] evts;
   });
 
-  uint64_t event_age[unique_evts] = {0};
+  uint64_t event_age[unique_evts];
+  memset(event_age, 0, unique_evts * sizeof(uint64_t));
   if (core::Runtime::runtime_singleton_->KfdVersion().supports_event_age)
     for (uint32_t i = 0; i < unique_evts; i++)
       event_age[i] = 1;