Convert negative zero in ArraySpeciesCreate

src/js/array.js

 // Copyright 2012 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, extrasUtils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
@@ skipping 25 matching lines @@
 
 utils.ImportFromExperimental(function(from) {
   FLAG_harmony_species = from.FLAG_harmony_species;
 });
 
 // -------------------------------------------------------------------
 
 
 function ArraySpeciesCreate(array, length) {
   var constructor;
+
+  if (1 / length === -INFINITY) {
+    length = 0;
+  }

[Dan Ehrenberg, 2016/05/04 16:44:48]

A likely faster way to convert -0 to +0 is length += 0. This is done in
InnerArrayIndexOf, for example. Maybe we should add a macro which implements it.

+
   if (FLAG_harmony_species) {
     constructor = %ArraySpeciesConstructor(array);
   } else {
     constructor = GlobalArray;
   }
   return new constructor(length);
 }
 
 
 function KeySortCompare(a, b) {
@@ skipping 1734 matching lines @@
 %InstallToContext([
   "array_pop", ArrayPop,
   "array_push", ArrayPush,
   "array_shift", ArrayShift,
   "array_splice", ArraySplice,
   "array_slice", ArraySlice,
   "array_unshift", ArrayUnshift,
 ]);
 
 });