test-bus freezes with WSACreateEvent/WSAEventSelect based implementation of dbus_poll in Windows
With !78 one task is to provide a poll implementation based on WSACreateEvent/WSAEventSelect to be able to wait on handles and sockets in one system call. Fortunally dbus windows source code already provides a related implementation https://gitlab.freedesktop.org/dbus/dbus/blob/master/dbus/dbus-sysdeps-win.c#L1170.
A quick test showed that this implementation is in a state that for example dbus-send/dbus-monitor can connect to dbus-daemon and can call dbus methods.
In the opposite the dispatch tests from test-bus are not working and freezes and need to be fixed.