Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.
Reviewed by: ru
Approved by: philip, ed (mentors)
does not return a list of ASCII NUL terminated strings.
Instead, a list of attribute names is returned, where each
list entry consists of one byte for the name length, followed
by the name, without a terminating ASCII NUL.
This in similar to change 1.17 to extattr_get_file.2
Reviewed by: rwatson, ru
