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

test/mjsunit/regress/regress-builtin-array-op.js

 // Copyright 2012 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 17 matching lines @@
 // Test that we invoke the correct sort function in
 // array operations.
 
 var foo =  "hest";
 Array.prototype.sort = function(fn) { foo = "fisk"; };
 Function.prototype.call = function() { foo = "caramel"; };
 var a = [2,3,1];
 a[100000] = 0;
 a.join();
 assertEquals("hest", foo);
-