Allow getters and setters on JSArray elements.

test/mjsunit/indexed-accessors.js

 // Copyright 2009 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 63 matching lines @@
 }
 actual[1000000] = -1;
 testArray();
 testArray();
 actual.__defineGetter__('0', function() { return expected[0]; });
 expected[0] = 42;
 testArray();
 expected[0] = 111;
 testArray();
 
-// The functionality is not implemented for arrays due to performance issues.
-var a = [ 1 ];
-a.__defineGetter__('2', function() { return 7; });
-assertEquals(undefined, a[2]);
-assertEquals(1, a.length);
-var b = 0;
-a.__defineSetter__('5', function(y) { b = y; });
-assertEquals(1, a.length);
-a[5] = 42;
-assertEquals(0, b);
-assertEquals(42, a[5]);
-assertEquals(6, a.length);
-
 // Using a setter where only a getter is defined throws an exception.
 var q = {};
 q.__defineGetter__('0', function() { return 42; });
 assertThrows('q[0] = 7');
 
 // Using a getter where only a setter is defined returns undefined.
 var q1 = {};
 q1.__defineSetter__('0', function() {q1.b = 17;});
 assertEquals(q1[0], undefined);
 // Setter works
 q1[0] = 3;
 assertEquals(q1[0], undefined);
 assertEquals(q1.b, 17);
 
 // Complex case of using an undefined getter.
 // From http://code.google.com/p/v8/issues/detail?id=298
 // Reported by nth10sd.
 
 a = function() {};
 __defineSetter__("0", function() {});
 if (a |= '') {};
 assertThrows('this[a].__parent__');
 assertEquals(a, 0);
 assertEquals(this[a], undefined);