bpo-39481: PEP 585 for a variety of modules (GH-19423)

- concurrent.futures
- ctypes
- http.cookies
- multiprocessing
- queue
- tempfile
- unittest.case
- urllib.parse

Lib/unittest/case.py

@@ -241,6 +241,8 @@ class _AssertRaisesContext(_AssertRaisesBaseContext):
                      expected_regex.pattern, str(exc_value)))
         return True
 
+    __class_getitem__ = classmethod(types.GenericAlias)
+
 
 class _AssertWarnsContext(_AssertRaisesBaseContext):
     """A context manager used to implement TestCase.assertWarns* methods."""