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

test/mjsunit/unicode-test.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 9147 matching lines @@
     }
   }
   print ("re = " + out);
 }
 
 var thai_l_thingy = "\u0e44";
 var thai_l_regexp = new RegExp(thai_l_thingy);
 var thai_l_regexp2 = new RegExp("[" + thai_l_thingy + "]");
 assertTrue(thai_l_regexp.test(thai_l_thingy));
 assertTrue(thai_l_regexp2.test(thai_l_thingy));
-
-