Add 'part of' in dart2js code.

lib/compiler/implementation/ssa/types.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.
 
+part of ssa;
+
 abstract class HType {
   const HType();
 
   /**
    * Returns an [HType] that represents [type] and all types that have
    * [type] as supertype.
    */
   factory HType.fromBoundedType(DartType type,
                                 Compiler compiler,
                                 [bool canBeNull = false]) {
@@ skipping 852 matching lines @@
   operator [](HInstruction instruction) {
     HType result = _map[instruction];
     if (result == null) return instruction.guaranteedType;
     return result;
   }
 
   operator []=(HInstruction instruction, HType value) {
     _map[instruction] = value;
   }
 }