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

test/mjsunit/arguments.js

 // Copyright 2011 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 169 matching lines @@
 assertArrayEquals([1, void 0], f1(3));
 assertArrayEquals([2, 5, 5], f1(3, 5));
 assertArrayEquals([3, 5, 5, 7], f1(3, 5, 7));
 
 // Check out of bounds behavior.
 function arg_get(x) { return arguments[x]; }
 function arg_del(x) { return delete arguments[x]; }
 function arg_set(x) { return (arguments[x] = 117); }
 assertEquals(undefined, arg_get(0xFFFFFFFF));
 assertEquals(true, arg_del(0xFFFFFFFF));
-assertEquals(117, arg_set(0xFFFFFFFF));
+assertEquals(117, arg_set(0xFFFFFFFF));