SYSCTL_SIZEOF() has been introduced in FreeBSD by commit "sysctl(9):
Ease exporting struct sizes; Discourage doing that" (713abc9880aa) in
branch 'main'. It will soon be backported to 'stable/14'. We will thus
be able to remove the old, alternate version left in the '#else' branch
as soon as 'stable/13' goes out of support (April 30, 2026).
Sponsored-by: The FreeBSD Foundation
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Olivier Certner <olce@FreeBSD.org>
Closes#17309