Move more builtin files to strict mode.

src/apinatives.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.
 
+"use strict";
+
 // This file contains infrastructure used by the API.  See
 // v8natives.js for an explanation of these files are processed and
 // loaded.
 
 
 function CreateDate(time) {
   var date = new $Date();
   date.setTime(time);
   return date;
 }
@@ skipping 91 matching lines @@
             obj, name, getter, setter, attribute, access_control);
       } else {
         throw "Bad properties array";
       }
       i += length + 1;
     }
   } finally {
     if (requires_access_checks) %EnableAccessChecks(obj);
   }
 }