bpo-46716: Use strict unsigned long conversion for DWORD values

[jkloth]

The second part of the fix for negative timeouts.

This PR should not be backported for the reasons I state here: #32079 (comment)
To further emphasize this, see the additional change required in this PR for use of -1 to denote INFINITE.

https://bugs.python.org/issue46716

[eryksun]

Maybe we should start to gradually add test cases for _winapi in "Lib/test/test_os.py", even if it's only an internal module. For example:

@unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
class Win32APITests(unittest.TestCase):

    def test_dword_convert_negative(self):
        with self.assertRaises(ValueError):
            for h in _winapi.CreatePipe(None, -1):
                _winapi.CloseHandle(h)

    def test_dword_convert_overflow(self):
        with self.assertRaises(OverflowError):
            for h in _winapi.CreatePipe(None, 1 << 32):
                _winapi.CloseHandle(h)

[serhiy-storchaka]

The DWORD converter is also used in winreg.c and overlapped.c.

[serhiy-storchaka]

You can use DWORD(bitwise=True) instead of DWORD in places where you want to keep the old behavior.

Or you can define non-strict by default completely compatible converter:

class DWORD_converter(unsigned_long_converter):
    type = 'DWORD'

    def converter_init(self, *, bitwise: bool = True) -> None:
        super().converter_init(bitwise=bitwise)

and use DWORD(bitwise=False) if you need a strict conversion.