Fix hints reported by analyzer.

pkg/compiler/lib/src/elements/modelx.dart

 // Copyright (c) 2013, 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 elements.modelx;
 
 import '../common.dart';
 import '../common/names.dart' show Identifiers;
 import '../common/resolution.dart' show Resolution, ParsingContext;
 import '../compiler.dart' show Compiler;
@@ skipping 296 matching lines @@
   ErroneousConstructorElementX(MessageKind messageKind, Map messageArguments,
       String name, Element enclosing)
       : super(messageKind, messageArguments, name, enclosing);
 
   @override
   bool get isRedirectingGenerative => false;
 
   @override
   bool isRedirectingGenerativeInternal;
 
-  @override
   void set isRedirectingGenerative(_) {
     throw new UnsupportedError("isRedirectingGenerative");
   }
 
   @override
   bool get isRedirectingFactory => false;
 
   @override
   get definingElement {
     throw new UnsupportedError("definingElement");
@@ skipping 3093 matching lines @@
       body = node.asFunctionExpression().body;
     }
     return new ParsedResolvedAst(
         declaration,
         node,
         body,
         definingElement.treeElements,
         definingElement.compilationUnit.script.resourceUri);
   }
 }