G_TYPE_CHECK_INSTANCE_CAST() can trigger a "-Wcast-align":
src/core/devices/nm-device-macvlan.c: In function 'parent_changed_notify':
/usr/include/glib-2.0/gobject/gtype.h:2421:42: error: cast increases required alignment of target type [-Werror=cast-align]
2421 | # define _G_TYPE_CIC(ip, gt, ct) ((ct*) ip)
| ^
/usr/include/glib-2.0/gobject/gtype.h:501:66: note: in expansion of macro '_G_TYPE_CIC'
501 | #define G_TYPE_CHECK_INSTANCE_CAST(instance, g_type, c_type) (_G_TYPE_CIC ((instance), (g_type), c_type))
| ^~~~~~~~~~~
src/core/devices/nm-device-macvlan.h:13:6: note: in expansion of macro 'G_TYPE_CHECK_INSTANCE_CAST'
13 | (G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_DEVICE_MACVLAN, NMDeviceMacvlan))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
Avoid that by using _NM_G_TYPE_CHECK_INSTANCE_CAST().
This can only be done for our internal usages. The public headers
of libnm are not changed.
