We were not properly setting the new_descendent field
in Crossing structs for GTK_CROSSING_OUT events. This
was causing extraneous ::leave signals to be emitted,
and make model buttons in popover menus flicker when
hovered.
Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/2536
gtk_widget_handle_crossing (widget, &crossing, x, y);
if (crossing_type == GTK_CROSSING_POINTER)
gtk_widget_unset_state_flags (widget, GTK_STATE_FLAG_PRELIGHT);
+ prev = widget;
widget = gtk_widget_get_parent (widget);
}