Serialize / resynthesize 'isAsynchronous' and 'isGenerator' flags.

pkg/analyzer/test/src/summary/resynthesize_test.dart

Index: pkg/analyzer/test/src/summary/resynthesize_test.dart
diff --git a/pkg/analyzer/test/src/summary/resynthesize_test.dart b/pkg/analyzer/test/src/summary/resynthesize_test.dart
index faef708ca335b23ad86562de808a1220f828f45e..23dbd71c188ac4b4bd251b2082cb4351b6b5ecb5 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_test.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_test.dart
@@ -2916,6 +2916,20 @@ class C {
     checkLibrary('class C { var x = 0; }');
   }
 
+  test_function_async() {
+    checkLibrary(r'''
+import 'dart:async';
+Future f() async {}
+''');
+  }
+
+  test_function_asyncStar() {
+    checkLibrary(r'''
+import 'dart:async';
+Stream f() async* {}
+''');
+  }
+
   test_function_documented() {
     checkLibrary('''
 // Extra comment so doc comment offset != 0
@@ -3528,6 +3542,24 @@ get g {
     checkLibrary('export "a.dart";');
   }
 
+  test_member_function_async() {
+    checkLibrary(r'''
+import 'dart:async';
+class C {
+  Future f() async {}
+}
+''');
+  }
+
+  test_member_function_asyncStar() {
+    checkLibrary(r'''
+import 'dart:async';
+class C {
+  Stream f() async* {}
+}
+''');
+  }
+
   test_metadata_classDeclaration() {
     checkLibrary('const a = null; @a class C {}');
   }