Kill dead code in importlib.test.__main__ (#12019, reviewed by Brett Cannon)

Lib/importlib/test/__main__.py

@@ -4,7 +4,6 @@ Specifying the ``--builtin`` flag will run tests, where applicable, with
 builtins.__import__ instead of importlib.__import__.
 
 """
-import importlib
 from importlib.test.import_ import util
 import os.path
 from test.support import run_unittest
@@ -13,10 +12,6 @@ import unittest
 
 
 def test_main():
-    if '__pycache__' in __file__:
-        parts = __file__.split(os.path.sep)
-        start_dir = sep.join(parts[:-2])
-    else:
     start_dir = os.path.dirname(__file__)
     top_dir = os.path.dirname(os.path.dirname(start_dir))
     test_loader = unittest.TestLoader()