Add meta-kms and meta-monitor-manager-kms listener for the udev
device-removed signal and on this signal update the device state /
re-enumerate the monitors, so that the monitors properly get updated
to disconnected state on GPU removal.
We really should also have meta-backend-native remove the GPU itself
from our list of GPU objects. But that is more involved, see:
https://gitlab.gnome.org/GNOME/mutter/issues/710
This commit at least gets us to a point where we properly update the
list of monitors when a GPU gets unplugged; and where we no longer
crash the first time the user changes the monitor configuration after
a GPU was unplugged.
Specifically before this commit we would hit the first g_error () in
meta_renderer_native_create_view () as soon as some monitor
(re)configuration is done after a GPU was unplugged.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/713
f3660dc60e