Correct file names for tests in tests/language.

tests/language/type_variable_shadows_class.dart

Index: tests/language/type_variable_shadows_class.dart
===================================================================
--- tests/language/type_variable_shadows_class.dart	(revision 15191)
+++ tests/language/type_variable_shadows_class.dart	(working copy)
@@ -1,27 +0,0 @@
-// Copyright (c) 2012, 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.
-
-// A reference to a class that is shadowed by a type variable should still work
-// in a static context.
-
-class T {
-  String toString() => "Class T";
-  static String staticToString() => "Class T (static)";
-}
-
-class A<T> {
-  static method() {
-    var foo = new T();
-    Expect.equals("Class T", foo.toString());
-  }
-  instMethod() {
-    var foo = T.staticToString();
-    Expect.equals("Class T (static)", foo);
-  }
-}
-
-main() {
-  A.method();
-  new A<String>().instMethod();
-}