Enable ES6 iteration by default

src/unscopables.js

Index: src/unscopables.js
diff --git a/src/unscopables.js b/src/unscopables.js
index 0d70ac683f3200bc68881e47ad6f9eea8ab62fb4..fc030c68cb9f09cc7dd0c54f975bba1499d1c048 100644
--- a/src/unscopables.js
+++ b/src/unscopables.js
@@ -8,14 +8,14 @@
 // var $Array = global.Array;
 // var $Symbol = global.Symbol;
 
-function ExtendSymbol() {
+function UnscopablesExtendSymbol() {
   %CheckIsBootstrapping();
   InstallConstants($Symbol, $Array(
     "unscopables", symbolUnscopables
   ));
 }
 
-ExtendSymbol();
+UnscopablesExtendSymbol();
 
 
 var arrayUnscopables = {
@@ -30,10 +30,10 @@ var arrayUnscopables = {
 };
 
 
-function ExtendArrayPrototype() {
+function UnscopablesExtendArrayPrototype() {
   %CheckIsBootstrapping();
   %AddNamedProperty($Array.prototype, symbolUnscopables, arrayUnscopables,
                     DONT_ENUM | READ_ONLY);
 }
 
-ExtendArrayPrototype();
+UnscopablesExtendArrayPrototype();