Use function wrapper argument to expose internal arrays to native scripts.

src/templates.js

Index: src/templates.js
diff --git a/src/templates.js b/src/templates.js
index ff94683fb13c0909b3bb72bc801d6d68f818ee48..e49cb3ef734aff80d743a076221377af7ad68ee6 100644
--- a/src/templates.js
+++ b/src/templates.js
@@ -12,9 +12,17 @@ var $getTemplateCallSite;
 
 %CheckIsBootstrapping();
 
-var callSiteCache = new global.Map;
-var mapGetFn = global.Map.prototype.get;
-var mapSetFn = global.Map.prototype.set;
+// -------------------------------------------------------------------
+// Imports
+
+var GlobalMap = global.Map;
+var InternalArray = shared.InternalArray;
+
+// -------------------------------------------------------------------
+
+var callSiteCache = new GlobalMap;
+var mapGetFn = GlobalMap.prototype.get;
+var mapSetFn = GlobalMap.prototype.set;
 
 
 function SameCallSiteElements(rawStrings, other) {