Remove --harmony-async-await runtime flag

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index c99cadc481d0718e3bda6ee5b55c836e68392063..69118b31c42913b7fbd6a4cd34e705abba3c1559 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -3441,7 +3441,6 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_tailcalls)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(datetime_format_to_parts)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(icu_case_mapping)
 #endif
-EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_async_await)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_restrictive_generators)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_trailing_commas)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_class_fields)
@@ -4001,7 +4000,6 @@ bool Genesis::InstallExperimentalNatives() {
   static const char* datetime_format_to_parts_natives[] = {
       "native datetime-format-to-parts.js", nullptr};
 #endif
-  static const char* harmony_async_await_natives[] = {nullptr};
   static const char* harmony_restrictive_generators_natives[] = {nullptr};
   static const char* harmony_trailing_commas_natives[] = {nullptr};
   static const char* harmony_class_fields_natives[] = {nullptr};