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

test/mjsunit/math-pow.js

 // Copyright 2010 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 152 matching lines @@
       (1*((Math.pow(2,53))-1)*(Math.pow(2,-1074))) === 4.4501477170144023e-308);
   assertTrue(
       (1*(Math.pow(2,52))*(Math.pow(2,-1074))) === 2.2250738585072014e-308);
   assertTrue(
       (-1*(Math.pow(2,52))*(Math.pow(2,-1074))) === -2.2250738585072014e-308);
 }
 
 test();
 test();
 %OptimizeFunctionOnNextCall(test);
-test();
+test();