dart2js: Register constants in the model builder.

pkg/compiler/lib/src/js_emitter/program_builder.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 dart2js.js_emitter.program_builder;
 
 import 'js_emitter.dart' show computeMixinClass;
 import 'model.dart';
 
 import '../common.dart';
@@ skipping 426 matching lines @@
     // TODO(kasperl): This clearly doesn't work yet.
     js.Expression code = js.string("<<unimplemented>>");
     return new StaticMethod(element,
                             name, _registry.registerHolder(holder), code);
   }
 
   void _registerConstants(OutputUnit outputUnit,
                           List<ConstantValue> constantValues) {
     if (constantValues == null) return;
     for (ConstantValue constantValue in constantValues) {
+      _registry.registerConstant(outputUnit, constantValue);
       assert(!_constants.containsKey(constantValue));
       String name = namer.constantName(constantValue);
       String constantObject = namer.globalObjectForConstant(constantValue);
       Holder holder = _registry.registerHolder(constantObject);
       Constant constant = new Constant(name, holder, constantValue);
       _constants[constantValue] = constant;
     };
   }
 }