[bootstrapper] add checks for variable bindings in native scripts.

src/js/date.js

 // Copyright 2006-2008 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.
 
 // -------------------------------------------------------------------
 
 (function(global, utils) {
 
 "use strict";
 
@@ skipping 52 matching lines @@
   if (!IsFinite(min)) return NaN;
   if (!IsFinite(sec)) return NaN;
   if (!IsFinite(ms)) return NaN;
   return TO_INTEGER(hour) * msPerHour
       + TO_INTEGER(min) * msPerMinute
       + TO_INTEGER(sec) * msPerSecond
       + TO_INTEGER(ms);
 }
 
 
-// ECMA 262 - 15.9.1.12
-function TimeInYear(year) {
-  return DaysInYear(year) * msPerDay;
-}
-
-
 // Compute number of days given a year, month, date.
 // Note that month and date can lie outside the normal range.
 //   For example:
 //     MakeDay(2007, -4, 20) --> MakeDay(2006, 8, 20)
 //     MakeDay(2007, -33, 1) --> MakeDay(2004, 3, 1)
 //     MakeDay(2007, 14, -50) --> MakeDay(2007, 8, 11)
 function MakeDay(year, month, date) {
   if (!IsFinite(year) || !IsFinite(month) || !IsFinite(date)) return NaN;
 
   // Convert to integer and map -0 to 0.
@@ skipping 792 matching lines @@
   "toUTCString", DateToUTCString,
   "getYear", DateGetYear,
   "setYear", DateSetYear,
   "toISOString", DateToISOString,
   "toJSON", DateToJSON
 ]);
 
 %InstallToContext(["create_date_fun", CreateDate]);
 
 })