Fix detection of indexed properties in Object.defineProperty()

test/mjsunit/object-define-property.js

 // Copyright 2012 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 900 matching lines @@
 assertFalse(desc.configurable);
 
 // Define non existing property - all attributes should default to false.
 Object.defineProperty(arr, '15', descElement);
 desc = Object.getOwnPropertyDescriptor(arr, '15');
 assertEquals(desc.value, 'foobar');
 assertFalse(desc.writable);
 assertFalse(desc.enumerable);
 assertFalse(desc.configurable);
 
+// Define non-array property, check that .length is unaffected.
+assertEquals(16, arr.length);
+Object.defineProperty(arr, '0x20', descElement);
+assertEquals(16, arr.length);
+
 // See issue 968: http://code.google.com/p/v8/issues/detail?id=968
 var o = { x : 42 };
 Object.defineProperty(o, "x", { writable: false });
 assertEquals(42, o.x);
 o.x = 37;
 assertEquals(42, o.x);
 
 o = { x : 42 };
 Object.defineProperty(o, "x", {});
 assertEquals(42, o.x);
@@ skipping 252 matching lines @@
   o.blubb = 123;
 }
 
 function C() {}
 
 Assign(new C);
 Assign(new C);
 %OptimizeFunctionOnNextCall(Assign);
 Object.defineProperty(C.prototype, "blubb", {get: function() { return -42; }});
 Assign(new C);