Change memberName and namedArguments in Invocation to use Symbol.

dart/tests/language/super_call4_test.dart

 // Copyright (c) 2012, 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.
 
 import "package:expect/expect.dart";
 
 // Checks that noSuchMethod is resolved in the super class and not in the
 // current class.
 
 class C {
   E e = new E();
 
   bool noSuchMethod(Invocation im) {
-    if (im.memberName == 'foo') {
+    if (im.memberName == const Symbol('foo')) {
       return im.positionalArguments.isEmpty &&
              im.namedArguments.isEmpty &&
              im.invokeOn(e);
     }
-    if (im.memberName == 'bar') {
+    if (im.memberName == const Symbol('bar')) {
       return im.positionalArguments.length == 1 &&
              im.namedArguments.isEmpty &&
              im.invokeOn(e);
     }
-    if (im.memberName == 'baz') {
+    if (im.memberName == const Symbol('baz')) {
       return im.positionalArguments.isEmpty &&
              im.namedArguments.length == 1 &&
              im.invokeOn(e);
     }
-    if (im.memberName == 'boz') {
+    if (im.memberName == const Symbol('boz')) {
       return im.positionalArguments.length == 1 &&
              im.namedArguments.length == 1 &&
              im.invokeOn(e);
     }
     return false;
   }
 }
 
 class D extends C {
   bool noSuchMethod(Invocation im) {
@@ skipping 20 matching lines @@
   bool boz(int a, {int c}) => a == 1 && c == 2;
 }
 
 main() {
   var d = new D();
   Expect.isTrue(d.test1());
   Expect.isTrue(d.test2());
   Expect.isTrue(d.test3());
   Expect.isTrue(d.test4());
 }