[test] Fix deterministic test shards.

tools/testrunner/objects/testcase.py

 # Copyright 2012 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 82 matching lines @@
       return self.override_shell
     return self.suite.shell()
 
   def __getstate__(self):
     """Representation to pickle test cases.
 
     The original suite won't be sent beyond process boundaries. Instead
     send the name only and retrieve a process-local suite later.
     """
     return dict(self.__dict__, suite=self.suite.name)
+
+  def __cmp__(self, other):
+    # Make sure that test cases are sorted correctly if sorted without
+    # key function. But using a key function is preferred for speed.
+    return cmp(
+        (self.suite.name, self.path, self.flags),
+        (other.suite.name, other.path, other.flags),
+    )