gio: add support for g_auto() and g_autoptr()

Add support to libgio types for the new cleanup macros.

https://bugzilla.gnome.org/show_bug.cgi?id=743640

gio/gunixmount.h

@@ -33,6 +33,7 @@ G_BEGIN_DECLS
 #define G_UNIX_MOUNT_CLASS(k)    (G_TYPE_CHECK_CLASS_CAST((k), G_TYPE_UNIX_MOUNT, GUnixMountClass))
 #define G_IS_UNIX_MOUNT(o)       (G_TYPE_CHECK_INSTANCE_TYPE ((o), G_TYPE_UNIX_MOUNT))
 #define G_IS_UNIX_MOUNT_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE ((k), G_TYPE_UNIX_MOUNT))
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GUnixMount, g_object_unref)
 
 typedef struct _GUnixMountClass GUnixMountClass;