Use the LookupIterator for SetElement and friends

src/harmony-array.js

 // Copyright 2013 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.
 
 (function(global, utils) {
 
 'use strict';
 
 %CheckIsBootstrapping();
 
@@ skipping 220 matching lines @@
         result.length = k;
         return result;
       }
 
       nextValue = next.value;
       if (mapping) {
         mappedValue = %_CallFunction(receiver, nextValue, k, mapfn);
       } else {
         mappedValue = nextValue;
       }
-      %AddElement(result, k++, mappedValue, NONE);
+      // TODO(verwaest): This should redefine rather than adding.
+      %AddElement(result, k++, mappedValue);
     }
   } else {
     var len = $toLength(items.length);
     result = %IsConstructor(this) ? new this(len) : new GlobalArray(len);
 
     for (k = 0; k < len; ++k) {
       nextValue = items[k];
       if (mapping) {
         mappedValue = %_CallFunction(receiver, nextValue, k, mapfn);
       } else {
         mappedValue = nextValue;
       }
-      %AddElement(result, k, mappedValue, NONE);
+      // TODO(verwaest): This should redefine rather than adding.
+      %AddElement(result, k, mappedValue);
     }
 
     result.length = k;
     return result;
   }
 }
 
 // ES6, draft 05-22-14, section 22.1.2.3
 function ArrayOf() {
   var length = %_ArgumentsLength();
   var constructor = this;
   // TODO: Implement IsConstructor (ES6 section 7.2.5)
   var array = %IsConstructor(constructor) ? new constructor(length) : [];
   for (var i = 0; i < length; i++) {
-    %AddElement(array, i, %_Arguments(i), NONE);
+    // TODO(verwaest): This should redefine rather than adding.
+    %AddElement(array, i, %_Arguments(i));
   }
   array.length = length;
   return array;
 }
 
 // -------------------------------------------------------------------
 
 utils.InstallConstants(GlobalSymbol, [
   // TODO(dslomov, caitp): Move to symbol.js when shipping
   "isConcatSpreadable", symbolIsConcatSpreadable
@@ skipping 24 matching lines @@
 
 utils.Export(function(to) {
   to.ArrayFrom = ArrayFrom;
   to.InnerArrayCopyWithin = InnerArrayCopyWithin;
   to.InnerArrayFill = InnerArrayFill;
   to.InnerArrayFind = InnerArrayFind;
   to.InnerArrayFindIndex = InnerArrayFindIndex;
 });
 
 })