X64: Faster push/pop implementation.

test/mjsunit/array-pop.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 40 matching lines @@
 
     assertEquals(7, a.pop(), "7th pop");
     assertEquals(0, a.length, "length 7th pop");
 
     assertEquals(undefined, a.pop(), "8th pop");
     assertEquals(0, a.length, "length 8th pop");
 
     assertEquals(undefined, a.pop(1, 2, 3), "9th pop");
     assertEquals(0, a.length, "length 9th pop");
   }
+
+  // Check that pop works on inherited properties.
+  for (var i = 0; i < 10 ;i++) {  // Ensure ICs are stabilized.
+    Array.prototype[1] = 1;
+    Array.prototype[3] = 3;
+    Array.prototype[5] = 5;
+    Array.prototype[7] = 7;
+    Array.prototype[9] = 9;
+    a = [0,1,2,,4,,6,7,8,,];
+    assertEquals(10, a.length, "inherit-initial-length");
+    for (var j = 9; j >= 0; j--) {
+      assertEquals(j + 1, a.length, "inherit-pre-length-" + j);
+      assertTrue(j in a, "has property " + j);
+      var own = a.hasOwnProperty(j);
+      var inherited = Array.prototype.hasOwnProperty(j);
+      assertEquals(j, a.pop(), "inherit-pop");
+      assertEquals(j, a.length, "inherit-post-length");
+      assertFalse(a.hasOwnProperty(j), "inherit-deleted-own-" + j);
+      assertEquals(inherited, Array.prototype.hasOwnProperty(j),
+                   "inherit-not-deleted-inherited" + j);
+    }
+    Array.prototype.length = 0;  // Clean-up.
+  }
 })();
 
 // Test the case of not JSArray receiver.
 // Regression test for custom call generators, see issue 684.
 (function() {
   var a = [];
   for (var i = 0; i < 100; i++) a.push(i);
   var x = {__proto__: a};
   for (var i = 0; i < 100; i++) {
     assertEquals(99 - i, x.pop(), i + 'th iteration');
   }
 })();