[strong] make function and class declarations lexical & immutable

test/mjsunit/strong/classes.js

Index: test/mjsunit/strong/classes.js
diff --git a/test/mjsunit/strong/classes.js b/test/mjsunit/strong/classes.js
new file mode 100644
index 0000000000000000000000000000000000000000..3c7caf5f84e4a5d31ac3519d975816a4be05ae8b
--- /dev/null
+++ b/test/mjsunit/strong/classes.js
@@ -0,0 +1,17 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --strong-mode
+
+'use strong';
+
+class C {}
+
+(function ImmutableClassBindings() {
+  class D {}
+  assertThrows(function(){ eval("C = 0") }, TypeError);
+  assertThrows(function(){ eval("D = 0") }, TypeError);
+  assertEquals('function', typeof C);
+  assertEquals('function', typeof D);
+})();