Wrap map and set implementation in functions.

src/templates.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-"use strict";
+// Called from a desugaring in the parser.
 
-// Called from a desugaring in the parser.
-var GetTemplateCallSite;
+var $getTemplateCallSite;
 
 (function() {
 
+"use strict";
+
 %CheckIsBootstrapping();
 
-var callSiteCache = new $Map;
-var mapGetFn = $Map.prototype.get;
-var mapSetFn = $Map.prototype.set;
+var callSiteCache = new global.Map;
+var mapGetFn = global.Map.prototype.get;
+var mapSetFn = global.Map.prototype.set;
 
 
 function SameCallSiteElements(rawStrings, other) {
   var length = rawStrings.length;
   var other = other.raw;
 
   if (length !== other.length) return false;
 
   for (var i = 0; i < length; ++i) {
     if (rawStrings[i] !== other[i]) return false;
@@ skipping 24 matching lines @@
     array[0] = siteObj;
     %_CallFunction(callSiteCache, hash, array, mapSetFn);
   } else {
     obj.push(siteObj);
   }
 
   return siteObj;
 }
 
 
-GetTemplateCallSite = function(siteObj, rawStrings, hash) {
+$getTemplateCallSite = function(siteObj, rawStrings, hash) {
   var cached = GetCachedCallSite(rawStrings, hash);
 
   if (!IS_UNDEFINED(cached)) return cached;
 
   %AddNamedProperty(siteObj, "raw", %ObjectFreeze(rawStrings),
       READ_ONLY | DONT_ENUM | DONT_DELETE);
 
   return SetCachedCallSite(%ObjectFreeze(siteObj), hash);
 }
 
 })();