Add ERR_MEMORY exit code to show that there was not enough memory; fix debug.stm build

src/libruntime/jerry-exit.c

@@ -66,6 +66,9 @@ jerry_exit( jerry_status_t code) /**< status code */
       case ERR_PARSER:
         __printf("ERR_PARSER\n");
         break;
+      case ERR_MEMORY:
+        __printf("ERR_MEMORY\n");
+        break;
       case ERR_GENERAL:
         __printf("ERR_GENERAL\n");
         break;