FreeBSD 12, specifically __FreeBSD_version 1200026 and later, no longer
exposes struct inpcb and struct tcpcb to userland.  New structs xinpcb
and xtcpcb shall be used instead.
Signed-off-by: Gerald Pfeifer <gerald@pfeifer.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>