Add support for reporting vm faults through the queue error handler.

Under xnack we can now identify the queue which generated a vm fault.
This allows users to identify which queue, and therefore which
dispatch, a vm fault came from.

Change-Id: If72ff3de05800f2b811aa7842a15eedff8b5e45a

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

@@ -2758,6 +2758,10 @@ hsa_status_t hsa_status_string(
       *status_string =
           "HSA_EXT_STATUS_ERROR_DIRECTIVE_MISMATCH: Directive mismatch";
       break;
+    case HSA_STATUS_ERROR_MEMORY_FAULT:
+      *status_string =
+          "HSA_STATUS_ERROR_MEMORY_FAULT: Agent attempted to access an inaccessible address.";
+      break;
     default:
       return HSA_STATUS_ERROR_INVALID_ARGUMENT;
   }