This is an analogous commit to c1f5e528. The original fix only touched
gtype.h and not gtypemodule.h.
The *_init() functions have prototypes incompatible with *InitFunc types they
are being cast to. This upsets GCC 8's -Wcast-function-type that's enabled by
default with -Wextra.
Let's not have the public header files emit a warning and neutralize it by
doing a void(*)(void) cast first.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
https://gitlab.gnome.org/GNOME/glib/issues/1666