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

- concurrent.futures
- ctypes
- http.cookies
- multiprocessing
- queue
- tempfile
- unittest.case
- urllib.parse
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index 5e5d535..d0ee561 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -241,6 +241,8 @@
                      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."""