Bump to v4.13.0.

_getSymbols.js

@@ -1,3 +1,5 @@
+var stubArray = require('./stubArray');
+
 /** Built-in value references. */
 var getOwnPropertySymbols = Object.getOwnPropertySymbols;
 
@@ -16,9 +18,7 @@ function getSymbols(object) {
 
 // Fallback for IE < 11.
 if (!getOwnPropertySymbols) {
-  getSymbols = function() {
-    return [];
-  };
+  getSymbols = stubArray;
 }
 
 module.exports = getSymbols;