This change broke buildbots.

$ ./python -We -m test.regrtest test_os 
Run tests sequentially
0:00:00 [1/1] test_os
test test_os crashed -- Traceback (most recent call last):
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 151, in runtest_inner
    the_module = importlib.import_module(abstest)
  File "/home/serhiy/py/cpython/Lib/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 978, in _gcd_import
  File "<frozen importlib._bootstrap>", line 961, in _find_and_load
  File "<frozen importlib._bootstrap>", line 950, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 655, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 677, in exec_module
  File "<frozen importlib._bootstrap>", line 205, in _call_with_frames_removed
  File "/home/serhiy/py/cpython/Lib/test/test_os.py", line 5, in <module>
    import asynchat
  File "/home/serhiy/py/cpython/Lib/asynchat.py", line 48, in <module>
    import asyncore
  File "/home/serhiy/py/cpython/Lib/asyncore.py", line 65, in <module>
    PendingDeprecationWarning, stacklevel=2)
PendingDeprecationWarning: asyncore module is deprecated in 3.6. Use asyncio instead.

test_os failed

1 test failed:
    test_os

Total duration: 59 ms
Tests result: FAILURE