Add test case for SparseJoin misbehavior with getters

BUG=v8:3621
LOG=N
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/645703003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24535 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/bugs/bug-3621.js

+// 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.
+
+var a = [];
+var endIndex = 0xffff;
+a[endIndex] = 3;
+Object.defineProperty(a, 0, { get: function() { this[1] = 2; return 1; } });
+assertEquals('123', a.join(''));
+delete a[1];  // reset the array
+assertEquals('1,2,', a.join().slice(0, 4));