Revert "Fix null.runtimeType, reflect(null).type.superinterfaces, and reflect(null).getField."

tests/lib/mirrors/null_test.dart

Index: tests/lib/mirrors/null_test.dart
diff --git a/tests/lib/mirrors/null_test.dart b/tests/lib/mirrors/null_test.dart
index d0069d288d0221dc193cbf1e87b7bfb76b333b5b..72f5e23c7fbef2778e3cba073075ef25a8082aa6 100644
--- a/tests/lib/mirrors/null_test.dart
+++ b/tests/lib/mirrors/null_test.dart
@@ -28,8 +28,8 @@ main() {
   ClassMirror NullMirror = nullMirror.type;
   Expect.equals(reflectClass(Null), NullMirror);
   Expect.equals(#Null, NullMirror.simpleName);
-  Expect.equals(#Object, NullMirror.superclass.simpleName);  /// 00: ok
-  Expect.equals(null, NullMirror.superclass.superclass);  /// 00: continued
+  Expect.equals(#Object, NullMirror.superclass.simpleName);
+  Expect.equals(null, NullMirror.superclass.superclass);
   Expect.listEquals([], NullMirror.superinterfaces);
   Expect.equals(currentMirrorSystem().libraries[Uri.parse('dart:core')],
                 NullMirror.owner);