dart2js: add mangled-global-names embedded global to new emitter.

pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart

Index: pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart b/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
index 763acd96436f22d46d3554a08a5b3460a4645e53..8f4ac995b30eeaff36b6d391135887602c29b629 100644
--- a/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/new_emitter/model_emitter.dart
@@ -17,7 +17,8 @@ import 'package:_internal/compiler/js_lib/shared/embedded_names.dart' show
     GET_TYPE_FROM_NAME,
     INITIALIZE_LOADED_HUNK,
     IS_HUNK_INITIALIZED,
-    IS_HUNK_LOADED;
+    IS_HUNK_LOADED,
+    MANGLED_GLOBAL_NAMES;
 
 import '../js_emitter.dart' show NativeGenerator;
 import '../model.dart';
@@ -157,6 +158,9 @@ class ModelEmitter {
       globals.add(emitInitializeLoadedHunk());
     }
 
+    globals.add(new js.Property(js.string(MANGLED_GLOBAL_NAMES),
+                                js.js('Object.create(null)', [])));
+
     globals.add(emitGetTypeFromName());
     js.ObjectInitializer globalsObject = new js.ObjectInitializer(globals);