multiple test failures in version 0.4 with pypy3

[jlec]

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ERROR: test_signature_on_callable_objects (tests.test_inspect.TestSignatureObject)
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Traceback (most recent call last):
  File "/var/tmp/portage/dev-python/funcsigs-0.4/work/funcsigs-0.4/tests/test_inspect.py", line 508, in test_signature_on_callable_objects
    self.assertEqual(self.signature(Foo()),
  File "/var/tmp/portage/dev-python/funcsigs-0.4/work/funcsigs-0.4/tests/test_inspect.py", line 17, in signature
    sig = inspect.signature(func)
  File "/var/tmp/portage/dev-python/funcsigs-0.4/work/funcsigs-0.4/funcsigs/__init__.py", line 176, in signature
    raise ValueError('callable {0!r} is not supported by signature'.format(obj))
ValueError: callable <tests.test_inspect.Foo object at 0x0000000001405948> is not supported by signature

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ERROR: test_signature_on_class (tests.test_inspect.TestSignatureObject)
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Traceback (most recent call last):
  File "<string>", line 7, in test_signature_on_class
  File "/var/tmp/portage/dev-python/funcsigs-0.4/work/funcsigs-0.4/tests/test_inspect.py", line 17, in signature
    sig = inspect.signature(func)
  File "/var/tmp/portage/dev-python/funcsigs-0.4/work/funcsigs-0.4/funcsigs/__init__.py", line 176, in signature
    raise ValueError('callable {0!r} is not supported by signature'.format(obj))
ValueError: callable <class 'tests.test_inspect.C'> is not supported by signature

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[jlec]

pypy2 is fine.