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

test/mjsunit/enumeration-order.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 85 matching lines @@
 
 var expected = ['23', '42',  // indexed from 'o'
                 '-23', '300000000000', 'f', 'g', '-4',  // named from 'o'
                 '3', '5',  // indexed from 'proto1'
                 'd', 'e',  // named from 'proto1'
                 '2', '140000', '4294967295',  // indexed from 'proto2'
                 'a', 'b', 'c', '4294967296'];  // named from 'proto2'
 var actual = [];
 for (var p in o) actual.push(p);
 assertArrayEquals(expected, actual);
-
-
-
-