dart2js: Add an empty "MANGLED_NAMES" embedded global to the startup-emitter.

pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart

Index: pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart b/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
index f1bd2ca59e347f0e29a9f148daf61b12975f9f14..5fe72859ebd199d522c4f38087eb07455176e55c 100644
--- a/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
@@ -1020,6 +1020,11 @@ class FragmentEmitter {
 
     globals.add(emitMangledGlobalNames());
 
+    // The [MANGLED_NAMES] table is only relevant for reflection.
+    // TODO(floitsch): verify that this is correct.
+    globals.add(new js.Property(js.string(MANGLED_NAMES),
+                                new js.ObjectInitializer([])));
+
     globals.add(emitGetTypeFromName());
 
     globals.addAll(emitMetadata(program));