This was previously moved because nothing else in-tree uses it, but
evidently DilOS uses it out of tree.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Ryan Moeller <freqlabs@freebsd.org>
Closes#10361Closes#10685