Add SExpression test and share tests between dart2dart and analyzer2dart.

tests/compiler/dart2js/mock_libraries.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.
 
 // Library for creating mock versions of platform and internal libraries.
 
 library mock_libraries;
 
 String buildLibrarySource(
     Map<String, String> elementMap,
     [Map<String, String> additionalElementMap = const <String, String>{}]) {
   Map<String, String> map = new Map<String, String>.from(elementMap);
   if (additionalElementMap != null) {
     map.addAll(additionalElementMap);
   }
   StringBuffer sb = new StringBuffer();
   map.values.forEach((String element) {
     sb.write('$element\n');
   });
   return sb.toString();
 }
 
 const Map<String, String> DEFAULT_CORE_LIBRARY = const <String, String>{
   'bool': 'class bool {}',
+  'Comparator': 'abstract class Comparator<T> {}',
   'DateTime': r'''
       class DateTime {
         DateTime(year);
         DateTime.utc(year);
       }''',
+  'deprecated': 'const deprecated = 0;',
   'double': r'''
       abstract class double extends num {
         static var NAN = 0;
         static parse(s) {}
       }''',
   'Function': 'class Function {}',
   'identical': 'bool identical(Object a, Object b) { return true; }',
   'int': 'abstract class int extends num { }',
   'LinkedHashMap': r'''
       class LinkedHashMap {
@@ skipping 308 matching lines @@
   '_callInIsolate': 'var _callInIsolate;',
   '_WorkerBase': 'class _WorkerBase {}',
 };
 
 const Map<String, String> DEFAULT_MIRRORS_LIBRARY = const <String, String>{
   'Comment': 'class Comment {}',
   'MirrorSystem': 'class MirrorSystem {}',
   'MirrorsUsed': 'class MirrorsUsed {}',
 };