Stop reporting error when not parsing function bodies (issue 23460)

pkg/analyzer/lib/src/generated/parser.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.parser;
 
 import "dart:math" as math;
@@ skipping 5048 matching lines @@
             redirectedConstructor);
       }
     } else {
       body = _parseFunctionBody(
           true, ParserErrorCode.MISSING_FUNCTION_BODY, false);
       if (constKeyword != null &&
           factoryKeyword != null &&
           externalKeyword == null) {
         _reportErrorForToken(ParserErrorCode.CONST_FACTORY, factoryKeyword);
       } else if (body is EmptyFunctionBody) {
-        if (factoryKeyword != null && externalKeyword == null) {
+        if (factoryKeyword != null &&
+            externalKeyword == null &&
+            _parseFunctionBodies) {
           _reportErrorForToken(
               ParserErrorCode.FACTORY_WITHOUT_BODY, factoryKeyword);
         }
       } else {
         if (constKeyword != null) {
           _reportErrorForNode(
               ParserErrorCode.CONST_CONSTRUCTOR_WITH_BODY, body);
         } else if (!bodyAllowed) {
           _reportErrorForNode(
               ParserErrorCode.EXTERNAL_CONSTRUCTOR_WITH_BODY, body);
@@ skipping 5505 matching lines @@
   }
 
   /**
    * Copy resolution data from the [fromNode] to the [toNode].
    */
   static void copyResolutionData(AstNode fromNode, AstNode toNode) {
     ResolutionCopier copier = new ResolutionCopier();
     copier._isEqualNodes(fromNode, toNode);
   }
 }