bpo-36492: Deprecate passing some arguments as keyword arguments. (GH-12637)

Deprecated passing the following arguments as keyword arguments:

- "func" in functools.partialmethod(), weakref.finalize(),
  profile.Profile.runcall(), cProfile.Profile.runcall(),
  bdb.Bdb.runcall(), trace.Trace.runfunc() and
  curses.wrapper().
- "function" in unittest.addModuleCleanup() and
  unittest.TestCase.addCleanup().
- "fn" in the submit() method of concurrent.futures.ThreadPoolExecutor
  and concurrent.futures.ProcessPoolExecutor.
- "callback" in contextlib.ExitStack.callback(),
  contextlib.AsyncExitStack.callback() and
  contextlib.AsyncExitStack.push_async_callback().
- "c" and "typeid" in the create() method of multiprocessing.managers.Server
  and multiprocessing.managers.SharedMemoryServer.
- "obj" in weakref.finalize().

Also allowed to pass arbitrary keyword arguments (even "self" and "func")
if the above arguments are passed as positional argument.

Lib/test/test_functools.py

@@ -464,6 +464,7 @@ class TestPartialMethod(unittest.TestCase):
         positional = functools.partialmethod(capture, 1)
         keywords = functools.partialmethod(capture, a=2)
         both = functools.partialmethod(capture, 3, b=4)
+        spec_keywords = functools.partialmethod(capture, self=1, func=2)
 
         nested = functools.partialmethod(positional, 5)
 
@@ -497,6 +498,8 @@ class TestPartialMethod(unittest.TestCase):
 
         self.assertEqual(self.A.both(self.a, 5, c=6), ((self.a, 3, 5), {'b': 4, 'c': 6}))
 
+        self.assertEqual(self.a.spec_keywords(), ((self.a,), {'self': 1, 'func': 2}))
+
     def test_nested(self):
         self.assertEqual(self.a.nested(), ((self.a, 1, 5), {}))
         self.assertEqual(self.a.nested(6), ((self.a, 1, 5, 6), {}))
@@ -550,6 +553,14 @@ class TestPartialMethod(unittest.TestCase):
         with self.assertRaises(TypeError):
             class B(object):
                 method = functools.partialmethod(None, 1)
+        with self.assertRaises(TypeError):
+            class B:
+                method = functools.partialmethod()
+        with self.assertWarns(DeprecationWarning):
+            class B:
+                method = functools.partialmethod(func=capture, a=1)
+        b = B()
+        self.assertEqual(b.method(2, x=3), ((b, 2), {'a': 1, 'x': 3}))
 
     def test_repr(self):
         self.assertEqual(repr(vars(self.A)['both']),