[PATCH v3 4/7] winebus.sys: Introduce a new unixlib interface.

[Rémi Bernon]

FWIW, in case this needs a bit more context, the idea here is to 
ultimately have the "unix buses" work in a single thread each, and pass 
a pre-allocated "bus event" to the unix side with each "bus wait" call.

On return, the event (device creation, removal, or input report) will be 
processed on the Win32 side, and passed again to the next wait call for 
unix side cleanup, and to get the next event.

The device vtable will also go through the unixlib interface, to notify 
unix side of device start / remove, get their report descriptor and 
handle output and feature reports.
-- 
Rémi Bernon <rbernon at codeweavers.com>