On my PC, this patch also introduces two tests failure:

FAIL: test_log_destroyed_pending_task (test.test_asyncio.test_tasks.CTask_CFuture_SubclassTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py", line 1823, in test_log_destroyed_pending_task
    self.assertEqual(Task.all_tasks(loop=self.loop), set())
AssertionError: Items in the first set but not the second:
<Task pending coro=<BaseTaskTests.test_log_destroyed_pending_task.<locals>.kill_me() running at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:1796> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f649f135f18>()] created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:2001> created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:83>

======================================================================
FAIL: test_log_destroyed_pending_task (test.test_asyncio.test_tasks.CTask_CFuture_Tests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py", line 1823, in test_log_destroyed_pending_task
    self.assertEqual(Task.all_tasks(loop=self.loop), set())
AssertionError: Items in the first set but not the second:
<Task pending coro=<BaseTaskTests.test_log_destroyed_pending_task.<locals>.kill_me() running at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:1796> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f649f135498>()] created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:86> created at /home/angwer/cpython/Lib/asyncio/base_events.py:287>

======================================================================
FAIL: test_log_destroyed_pending_task (test.test_asyncio.test_tasks.CTask_PyFuture_Tests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py", line 1823, in test_log_destroyed_pending_task
    self.assertEqual(Task.all_tasks(loop=self.loop), set())
AssertionError: Items in the first set but not the second:
<Task pending coro=<BaseTaskTests.test_log_destroyed_pending_task.<locals>.kill_me() running at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:1796> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f649f135d98>()] created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:86> created at /home/angwer/cpython/Lib/asyncio/base_events.py:287>

======================================================================
FAIL: test_log_destroyed_pending_task (test.test_asyncio.test_tasks.PyTask_CFuture_Tests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py", line 1823, in test_log_destroyed_pending_task
    self.assertEqual(Task.all_tasks(loop=self.loop), set())
AssertionError: Items in the first set but not the second:
<Task pending coro=<BaseTaskTests.test_log_destroyed_pending_task.<locals>.kill_me() running at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:1796> wait_for=<Future pending cb=[Task._wakeup()] created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:86> created at /home/angwer/cpython/Lib/asyncio/base_events.py:287>

======================================================================
FAIL: test_log_destroyed_pending_task (test.test_asyncio.test_tasks.PyTask_PyFuture_SubclassTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py", line 1823, in test_log_destroyed_pending_task
    self.assertEqual(Task.all_tasks(loop=self.loop), set())
AssertionError: Items in the first set but not the second:
<Task pending coro=<BaseTaskTests.test_log_destroyed_pending_task.<locals>.kill_me() running at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:1796> wait_for=<Future pending cb=[add_subclass_tests.<locals>.Task._wakeup()] created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:2001> created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:83>

======================================================================
FAIL: test_log_destroyed_pending_task (test.test_asyncio.test_tasks.PyTask_PyFuture_Tests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py", line 1823, in test_log_destroyed_pending_task
    self.assertEqual(Task.all_tasks(loop=self.loop), set())
AssertionError: Items in the first set but not the second:
<Task pending coro=<BaseTaskTests.test_log_destroyed_pending_task.<locals>.kill_me() running at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:1796> wait_for=<Future pending cb=[Task._wakeup()] created at /home/angwer/cpython/Lib/test/test_asyncio/test_tasks.py:86> created at /home/angwer/cpython/Lib/asyncio/base_events.py:287>

======================================================================
FAIL: test_refcycle (test.test_generators.FinalizationTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/angwer/cpython/Lib/test/test_generators.py", line 54, in test_refcycle
    self.assertTrue(finalized)
AssertionError: False is not true

test test_generators failed
test_generators failed

2 tests failed:
    test_asyncio test_generators

Total duration: 17 sec
Tests result: FAILURE