This patch does result in one functional change: if we are selecting for
AFD_POLL_READ on a socket which has had SD_RECEIVE and there are no asyncs, we
will now respond to POLLIN instead of ignoring it. Neither this nor the previous
behaviour matches Windows, which instead puts the socket into an aborted state
and sends RST to the peer if any data is received after SD_RECEIVE or if
SD_RECEIVE is done while there is pending data.

Apart from this there is no functional change, as the places where rd_shutdown
alone is checked can't be reached if there was a hangup. It is instead for
semantic clarity.
Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>