bpo-43682: Make staticmethod objects callable (GH-25117)

Static methods (@staticmethod) are now callable as regular functions.
diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py
index e94ebd3..9bde0c7 100644
--- a/Lib/test/test_pydoc.py
+++ b/Lib/test/test_pydoc.py
@@ -1142,7 +1142,7 @@ def sm(x, y):
                 '''A static method'''
                 ...
         self.assertEqual(self._get_summary_lines(X.__dict__['sm']),
-                         'sm(...)\n'
+                         'sm(x, y)\n'
                          '    A static method\n')
         self.assertEqual(self._get_summary_lines(X.sm), """\
 sm(x, y)