[elements] add fast-path for slice with FastSloppyArguments

test/mjsunit/array-slice.js

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 210 matching lines @@
 
 // Check slicing on arguments object.
 (function() {
   function func(expected, a0, a1, a2) {
     assertEquals(expected, Array.prototype.slice.call(arguments, 1));
   }
 
   func([]);
   func(['a'], 'a');
   func(['a', 1], 'a', 1);
+  func(['a', 1, 2, 3, 4, 5], 'a', 1, 2, 3, 4, 5);
   func(['a', 1, undefined], 'a', 1, undefined);
   func(['a', 1, undefined, void(0)], 'a', 1, undefined, void(0));
 })();
 
 // Check slicing on arguments object when missing arguments get assigined.
 (function() {
   function func(x, y) {
     assertEquals(1, arguments.length);
     assertEquals(undefined, y);
     y = 239;
@@ skipping 54 matching lines @@
 (function() {
   function f() {
     delete arguments[1];
     arguments.__proto__[1] = 5;
     var result = Array.prototype.slice.call(arguments);
     delete arguments.__proto__[1];
     assertEquals([1,5,3], result);
   }
   f(1,2,3);
 })();