Fix various parser bugs related to modifiers of top-level and class members.

dart/tests/compiler/dart2js/patch_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";
 import "../../../sdk/lib/_internal/compiler/implementation/dart2jslib.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/elements/elements.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/tree/tree.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/util/util.dart";
 import "mock_compiler.dart";
@@ skipping 488 matching lines @@
       external var foo;
       """,
       """
       patch get foo => 0;
       """);
   ensure(compiler, "foo", compiler.coreLibrary.find);
 
   Expect.isTrue(compiler.warnings.isEmpty,
                 "Unexpected warnings: ${compiler.warnings}");
   print('testPatchNonPatchableOrigin:${compiler.errors}');
-  Expect.equals(1, compiler.errors.length);
-  Expect.isTrue(
-      compiler.errors[0].message.kind == MessageKind.PATCH_NONPATCHABLE);
+  Expect.equals(2, compiler.errors.length);
+  Expect.equals(
+      MessageKind.EXTRANEOUS_MODIFIER, compiler.errors[0].message.kind);
+  Expect.equals(
+      // TODO(ahe): Eventually, this error should be removed as it will be
+      // handled by the regular parser.
+      MessageKind.PATCH_NONPATCHABLE, compiler.errors[1].message.kind);
 }
 
 testPatchNonExternalTopLevel() {
   var compiler = applyPatch(
       """
       void foo() {}
       """,
       """
       patch void foo() {}
       """);
@@ skipping 269 matching lines @@
   testPatchNoGetter();
   testPatchNonSetter();
   testPatchNoSetter();
   testPatchNonFunction();
 
   testPatchAndSelector();
 
   testAnalyzeAllInjectedMembers();
   testTypecheckPatchedMembers();
 }