dwarf_expr_current_offset(3) on FreeBSD
The text 17d46bae0a63, as FreeBSD 12.0-RELEASE, FreeBSD 11.4-RELEASE, FreeBSD 11.3-RELEASE, FreeBSD 11.2-RELEASE, FreeBSD 11.1-RELEASE, FreeBSD 11.0-RELEASE shipped it.
retrieve the number of bytes in a location expression stream