Get back recording 'implements' and 'extends' keyword on NodeList

tests/compiler/dart2js/unparser_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('dart:uri');
 #import('parser_helper.dart');
 #import("../../../lib/compiler/compiler.dart");
 #import("../../../lib/compiler/implementation/tree/tree.dart");
 
 testUnparse(String statement) {
@@ skipping 86 matching lines @@
   testUnparse('var x=new List<List<List<List<int>>>>();');
   testUnparse('var x=new List<List<List<List<List<int>>>>>();');
 }
 
 testForLoop() {
   testUnparse('for(;i<100;i++){}');
   testUnparse('for(i=0;i<100;i++){}');
 }
 
 testEmptyList() {
-  testUnparse('var x= [];');
+  testUnparse('var x=[];');
 }
 
 testClosure() {
   testUnparse('var x=(var x)=> x;');
 }
 
 testIndexedOperatorDecl() {
   testUnparseMember('operator[](int i)=> null;');
   testUnparseMember('operator[]=(int i,int j)=> null;');
 }
@@ skipping 308 matching lines @@
   testFactoryConstructor();
   testTopLevelField();
   testAbstractClass();
   testConflictLibraryClassRename();
   testNoConflictSendsRename();
   testConflictSendsRename();
   // Disabled with revert of https://chromiumcodereview.appspot.com/10824062/
   // testDefaultClassWithArgs();
   testClassExtendsWithArgs();
 }