Simplify collections.js now that it's wrapped in an IIFE

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.
+var GetTemplateCallSite;
+
+(function() {
+
+%CheckIsBootstrapping();
+
 var callSiteCache = new $Map;
+var mapGetFn = $Map.prototype.get;
+var mapSetFn = $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;
   }
 
   return true;
 }
 
 
 function GetCachedCallSite(siteObj, hash) {
-  var obj = %_CallFunction(callSiteCache, hash, $MapGet);
+  var obj = %_CallFunction(callSiteCache, hash, mapGetFn);
 
   if (IS_UNDEFINED(obj)) return;
 
   var length = obj.length;
   for (var i = 0; i < length; ++i) {
     if (SameCallSiteElements(siteObj, obj[i])) return obj[i];
   }
 }
 
 
 function SetCachedCallSite(siteObj, hash) {
-  var obj = %_CallFunction(callSiteCache, hash, $MapGet);
+  var obj = %_CallFunction(callSiteCache, hash, mapGetFn);
   var array;
 
   if (IS_UNDEFINED(obj)) {
     array = new InternalArray(1);
     array[0] = siteObj;
-    %_CallFunction(callSiteCache, hash, array, $MapSet);
+    %_CallFunction(callSiteCache, hash, array, mapSetFn);
   } else {
     obj.push(siteObj);
   }
 
   return siteObj;
 }
 
 
-function GetTemplateCallSite(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);
 }
+
+})();