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

test/mjsunit/regexp-indexof.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 56 matching lines @@
 assertEquals("xxxdefxxxdefxxx", "xxxabcxxxabcxxx".replace(/abc/g, "def"));
 assertEquals("o-o-oofo-ofo", "ofooofoooofofooofo".replace(/foo/g, "-"));
 assertEquals("deded", "deded".replace(/x/g, "-"));
 assertEquals("-a-b-c-d-e-f-", "abcdef".replace(new RegExp("", "g"), "-"));
 
 CheckMatch(/a(.)/, "xyzzyabxyzzzyacxyzzy", [[5, 2], [6, 1]]);
 CheckMatch(/a(.)/g, "xyzzyabxyzzyacxyzzy", [[5, 2], [12, 2]]);
 
 CheckMatch(/a|(?:)/g, "aba", [[0, 1], [1, 0], [2, 1], [3, 0]]);
 CheckMatch(/a|(?:)/g, "baba", [[0, 0], [1, 1], [2, 0], [3, 1], [4, 0]]);
-CheckMatch(/a|(?:)/g, "bab", [[0, 0], [1, 1], [2, 0], [3, 0]]);
+CheckMatch(/a|(?:)/g, "bab", [[0, 0], [1, 1], [2, 0], [3, 0]]);