Don't hide interceptors in mirrors.

tests/lib/mirrors/mirrors_test.dart

 // Copyright (c) 2011, 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 MirrorsTest;
 
 import 'dart:mirrors';
 
 import '../../light_unittest.dart';
 
@@ skipping 205 matching lines @@
   test("Test field access", () { testFieldAccess(mirrors); });
   test("Test closure mirrors", () { testClosureMirrors(mirrors); });
   test("Test invoke constructor", () { testInvokeConstructor(mirrors); });
   test("Test current library uri", () {
     testLibraryUri(new Class(),
       // TODO(floitsch): change this to "/mirrors_test.dart" when
       // dart2js_mirrors_test.dart has been removed.
       (Uri uri) => uri.path.endsWith('mirrors_test.dart'));
   });
   test("Test dart library uri", () {
-    testLibraryUri("test", (Uri uri) => uri == Uri.parse('dart:core'));
+    testLibraryUri("test",
+                   (Uri uri) {
+                     if (uri == Uri.parse('dart:core')) return true;
+                     // TODO(floitsch): do we want to fake the interceptors to
+                     // be in dart:core?
+                     return (uri == Uri.parse('dart:_interceptors'));
+                   });
   });
   test("Test simple and qualifiedName", () { testNames(mirrors); });
   test("Test reflect type", () { testReflectClass(mirrors); });
 }