From c4a0f62eef5e2482cc2c1604ee295f28f32372c4 Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Wed, 10 Dec 2014 21:12:01 +1100
Subject: [PATCH] add global symbol registry to polyfill

---
 lib/6to5/polyfill.js | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/6to5/polyfill.js b/lib/6to5/polyfill.js
index 9e98ba264a..e9f7342924 100644
--- a/lib/6to5/polyfill.js
+++ b/lib/6to5/polyfill.js
@@ -1,7 +1,7 @@
 /* jshint newcap: false */
 
 var ensureSymbol = function (key) {
-  Symbol[key] = Symbol[key] || Symbol();
+  Symbol[key] = Symbol[key] || Symbol(key);
 };
 
 var ensureProto = function (Constructor, key, val) {
@@ -13,11 +13,25 @@ var ensureProto = function (Constructor, key, val) {
 
 if (typeof Symbol === "undefined") {
   require("es6-symbol/implement");
+
+  var globSymbols = {};
+
+  Symbol.for = function (key) {
+    return globSymbols[key] = globSymbols[key] || Symbol(key);
+  };
+
+  Symbol.keyFor = function (sym) {
+    return sym.__description__;
+  };
 }
 
 require("es6-shim");
 require("./transformation/transformers/es6-generators/runtime");
 
+ensureSymbol("species");
+
+String.prototype.includes = String.prototype.includes || String.prototype.contains;
+
 // Abstract references
 
 ensureSymbol("referenceGet");