Fix polymorphic hydrogen handling of SLOPPY_ARGUMENTS_ELEMENTS

test/mjsunit/regress/regress-crbug-354391.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.
+
+// Flags: --allow-natives-syntax
+
+function load(a, i) {
+  return a[i];
+}
+
+function f2(a, b, c, d, index) {
+  return load(arguments, index);
+}
+
+f2(1, 2, 3, 4, "foo");
+f2(1, 2, 3, 4, "foo");
+load([11, 22, 33], 0);
+assertEquals(11, f2(11, 22, 33, 44, 0));
+
+%OptimizeFunctionOnNextCall(load);
+assertEquals(11, f2(11, 22, 33, 44, 0));