Serialize async marker on getters.

tests/compiler/dart2js/serialization/equivalence_test.dart

Index: tests/compiler/dart2js/serialization/equivalence_test.dart
diff --git a/tests/compiler/dart2js/serialization/equivalence_test.dart b/tests/compiler/dart2js/serialization/equivalence_test.dart
index 4e3d6e2d90962f60815d33d473c2194ac33958d9..80ebbdadffa12d0ef0fbdab2fbeacbd1196d61d8 100644
--- a/tests/compiler/dart2js/serialization/equivalence_test.dart
+++ b/tests/compiler/dart2js/serialization/equivalence_test.dart
@@ -28,6 +28,14 @@ import 'test_helper.dart';
 const TEST_SOURCES = const <String, String>{
   'main.dart': '''
 import 'a.dart' deferred as a;
+
+asyncMethod() async {}
+asyncStarMethod() async* {}
+syncStarMethod() sync* {}
+get asyncGetter async {}
+get asyncStarGetter async* {}
+get syncStarGetter sync* {}
+
 ''',
   'a.dart': '''
 ''',