Rename misnamed test file.

test/mjsunit/codegen-coverage.js

 // Copyright 2009 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 71 matching lines @@
     di = x + 1;
     // Locals are in the corresponding registers here.
     b = 0; // Free register ebx.
     assertEquals(a << d, 8);
 
     x = 3;
   }
 }
 
 cover_codegen_paths();