dart2js: add common names to mangledGlobalNames in 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 3546e185c9513994946a2b4569623299a1f1cff7..6e37f27edaf5e9bce1be9c4199c4851c21c1f9f6 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
@@ -6,6 +6,7 @@ library dart2js.new_js_emitter.model_emitter;
 
 import '../../dart2jslib.dart' show Compiler;
 import '../../dart_types.dart' show DartType;
+import '../../elements/elements.dart' show ClassElement;
 import '../../js/js.dart' as js;
 import '../../js_backend/js_backend.dart' show
     JavaScriptBackend,
@@ -32,6 +33,7 @@ import '../js_emitter.dart' show NativeGenerator, buildTearOffCode;
 import '../model.dart';
 
 
+
 class ModelEmitter {
   final Compiler compiler;
   final Namer namer;
@@ -209,8 +211,7 @@ class ModelEmitter {
                                   program.typeToInterceptorMap));
     }
 
-    globals.add(new js.Property(js.string(MANGLED_GLOBAL_NAMES),
-                                js.js('Object.create(null)', [])));
+    globals.add(emitMangledGlobalNames());
 
     globals.add(emitGetTypeFromName());
 
@@ -234,6 +235,24 @@ class ModelEmitter {
     return new js.Block(statements);
   }
 
+  js.Property emitMangledGlobalNames() {
+    List<js.Property> names = <js.Property>[];
+
+    // We want to keep the original names for the most common core classes when
+    // calling toString on them.
+    List<ClassElement> nativeClassesNeedingUnmangledName =
+        [compiler.intClass, compiler.doubleClass, compiler.numClass,
+         compiler.stringClass, compiler.boolClass, compiler.nullClass,
+         compiler.listClass];
+    nativeClassesNeedingUnmangledName.forEach((element) {
+        names.add(new js.Property(js.string(namer.getNameOfClass(element)),
+                                  js.string(element.name)));
+    });
+
+    return new js.Property(js.string(MANGLED_GLOBAL_NAMES),
+                           new js.ObjectInitializer(names));
+  }
+
   List<js.Property> emitLoadUrisAndHashes(Map<String, List<Fragment>> loadMap) {
     js.ArrayInitializer outputUris(List<Fragment> fragments) {
       return js.stringArray(fragments.map((DeferredFragment fragment) =>