We cannot just look for any declaration of qsort_r, because some
operating systems have a qsort_r that has a different prototype
but which still has a pair of pointers in the right places (the last two
args are interchanged): so use AC_LINK_IFELSE to check for both
known variants of qsort_r(), and swap their args into a consistent order
in a suitable inline function. (The code for this is taken almost
unchanged from gnulib.)
(Now we are not using AC_LIBOBJ any more, we can use a better name for
the qsort_r replacement as well.)
libctf/
* qsort_r.c: Rename to...
* ctf-qsort_r.c: ... this.
(_quicksort): Define to ctf_qsort_r.
* ctf-decls.h (qsort_r): Remove.
(ctf_qsort_r): Add.
(struct ctf_qsort_arg): New, transport the real ARG and COMPAR.
(ctf_qsort_compar_thunk): Rearrange the arguments to COMPAR.
* Makefile.am (libctf_a_LIBADD): Remove.
(libctf_a_SOURCES): New, add ctf-qsort_r.c.
* ctf-archive.c (ctf_arc_write): Call ctf_qsort_r, not qsort_r.
* ctf-create.c (ctf_update): Likewise.
* configure.ac: Check for BSD versus GNU qsort_r signature.
* Makefile.in: Regenerate.
* config.h.in: Likewise.
* configure: Likewise.
