Make sure files end with exactly one new line and police this in presubmit.

test/mjsunit/bugs/bug-1344252.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 58 matching lines @@
 var o1 = new Object();
 var o2 = new Object();
 // Add a z property to o1 to create a map transition.
 o1.z = 32;
 // Add a z accessor in the prototype chain for o1 and o2.
 Object.prototype.__defineSetter__('z', function(value) { result_z = value; });
 // The accessor should be called for o2.
 o2.z = 27;
 assertEquals(27, result_z);
 assertTrue(typeof o2.z == 'undefined');
-