add parser parseAsync flag

pkg/analyzer/lib/src/generated/engine.dart

 // Copyright (c) 2014, 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 analyzer.src.generated.engine;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 1029 matching lines @@
    * Return `true` if analysis is to generate dart2js related hint results.
    */
   bool get dart2jsHint;
 
   /**
    * Return `true` to enable custom assert messages (DEP 37).
    */
   bool get enableAssertMessage;
 
   /**
+   * Return `true` to if analysis is to include async support.

[Brian Wilkerson, 2016/01/08 18:43:47]

"if analysis is to include" --> "enable"

[danrubel, 2016/01/08 20:45:51]

Done.

+   */
+  bool get enableAsync;
+
+  /**
    * Return `true` to enable interface libraries (DEP 40).
    */
   bool get enableConditionalDirectives;
 
   /**
    * Return `true` to enable generic methods (DEP 22).
    */
   bool get enableGenericMethods => null;
 
   /**
@@ skipping 88 matching lines @@
    */
   bool dart2jsHint = false;
 
   /**
    * A flag indicating whether custom assert messages are to be supported (DEP
    * 37).
    */
   bool enableAssertMessage = false;
 
   /**
+   * A flag indicating whether analysis is to enable async support.
+   */
+  bool enableAsync = true;
+
+  /**
    * A flag indicating whether interface libraries are to be supported (DEP 40).
    */
   bool enableConditionalDirectives = false;
 
   /**
    * A flag indicating whether generic methods are to be supported (DEP 22).
    */
   bool enableGenericMethods = false;
 
   /**
@@ skipping 74 matching lines @@
 
   /**
    * Initialize a newly created set of analysis options to have the same values
    * as those in the given set of analysis [options].
    */
   AnalysisOptionsImpl.from(AnalysisOptions options) {
     analyzeFunctionBodiesPredicate = options.analyzeFunctionBodiesPredicate;
     cacheSize = options.cacheSize;
     dart2jsHint = options.dart2jsHint;
     enableAssertMessage = options.enableAssertMessage;
+    enableAsync = options.enableAsync;
     enableStrictCallChecks = options.enableStrictCallChecks;
     enableGenericMethods = options.enableGenericMethods;
     enableSuperMixins = options.enableSuperMixins;
     generateImplicitErrors = options.generateImplicitErrors;
     generateSdkErrors = options.generateSdkErrors;
     hint = options.hint;
     incremental = options.incremental;
     incrementalApi = options.incrementalApi;
     incrementalValidation = options.incrementalValidation;
     lint = options.lint;
@@ skipping 1146 matching lines @@
    * The data that was created from the source.
    */
   final E data;
 
   /**
    * Initialize a newly created holder to associate the given [data] with the
    * given [modificationTime].
    */
   TimestampedData(this.modificationTime, this.data);
 }