Fix for v8:3255 Grow KeyedStoreIC doesn't respect String value wrappers

test/mjsunit/regress/regress-3255.js

Index: test/mjsunit/regress/regress-3255.js
diff --git a/test/mjsunit/regress/regress-3255.js b/test/mjsunit/regress/regress-3255.js
new file mode 100644
index 0000000000000000000000000000000000000000..90d632c7baa859ff0f0da26ee4b7b2fbd13f3833
--- /dev/null
+++ b/test/mjsunit/regress/regress-3255.js
@@ -0,0 +1,20 @@
+// Copyright 2014 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: --allow-natives-syntax --enable-slow-asserts
+
+var arr = [];
+var str = new String('x');
+
+function f(a,b) {
+  a[b] = 1;
+}
+
+f(arr, 0);
+f(str, 0);
+f(str, 0);
+print(str);

[Michael Starzinger, 2014/04/04 16:41:26]

nit: The "print" seems obsolete.

+
+// This is just to trigger elements validation, object already broken.
+%SetProperty(str, 1, 'y', 0);