Add missing FrameState to JSToName nodes.

test/mjsunit/regress/regress-crbug-451770.js

Index: test/mjsunit/regress/regress-crbug-451770.js
diff --git a/test/mjsunit/regress/regress-crbug-451770.js b/test/mjsunit/regress/regress-crbug-451770.js
new file mode 100644
index 0000000000000000000000000000000000000000..942814a3169c7b04faefed3a2170df72d3411860
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-451770.js
@@ -0,0 +1,15 @@
+// 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: --harmony-computed-property-names --harmony-classes --harmony-sloppy
+
+assertThrows(function f() {
+  var t = { toString: function() { throw new Error(); } };
+  var o = { [t]: 23 };
+}, Error);
+
+assertThrows(function f() {
+  var t = { toString: function() { throw new Error(); } };
+  class C { [t]() { return 23; } };
+}, Error);