Log Message:
update raptor2 for netbsd-current having POSIX qsort_r().

with the new qsort_r() in -current, raptor2 is picking the wrong way
to use it on netbsd (and likely, on modern freebsd.)

as the _R_SORT_LINUX path is the POSIX version, use that on netbsd.

the lack of qsort_r(), ie, netbsd before a few days ago, makes it
provide it's own, differently named, backend for this functionality.

test-built on -current and netbsd-10.

no pkg bump because it doesn't affect the netbsd-10 or netbsd-9
(or non-netbsd) pkgs, and it merely fixes -current build, not makes
it better or different some how.