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

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

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.src.serialization.elements_test;
 
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
@@ skipping 2898 matching lines @@
   }
 
   test_field_static_final_untyped() {
     checkLibrary('class C { static final x = 0; }');
   }
 
   test_field_untyped() {
     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
 /**
  * Docs
  */
 f() {}''');
   }
 
   test_function_entry_point() {
@@ skipping 592 matching lines @@
 
   test_main_variable() {
     checkLibrary('var main;');
   }
 
   test_main_variable_via_export() {
     addLibrarySource('/a.dart', 'var main;');
     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 {}');
   }
 
   test_metadata_classTypeAlias() {
     checkLibrary(
         'const a = null; @a class C = D with E; class D {} class E {}');
   }
 
   test_metadata_constructor_call_named() {
@@ skipping 778 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }