Make all global private symbols own symbols.

src/string-iterator.js

Index: src/string-iterator.js
diff --git a/src/string-iterator.js b/src/string-iterator.js
index 7222885a56f465931980d646a277ea9c69cc1abf..cb578e77e789e0776a9a4165e3855c19801658c2 100644
--- a/src/string-iterator.js
+++ b/src/string-iterator.js
@@ -38,7 +38,7 @@ function StringIteratorIterator() {
 function StringIteratorNext() {
   var iterator = ToObject(this);
 
-  if (!HAS_PRIVATE(iterator, stringIteratorIteratedStringSymbol)) {
+  if (!HAS_DEFINED_PRIVATE(iterator, stringIteratorNextIndexSymbol)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['String Iterator.prototype.next']);
   }
@@ -52,7 +52,8 @@ function StringIteratorNext() {
   var length = TO_UINT32(s.length);
 
   if (position >= length) {
-    SET_PRIVATE(iterator, stringIteratorIteratedStringSymbol, UNDEFINED);
+    SET_PRIVATE(iterator, stringIteratorIteratedStringSymbol,
+                UNDEFINED);
     return CreateIteratorResultObject(UNDEFINED, true);
   }