xlc 13.1.0 crashes because of our may_alias attributes in nolibxml.c
on Power7. libxml.c and nolibxml.c are the only may_alias users for now,
so change our configure check to match the actual code using it.
Thanks to Paul Hargrove for reporting and debugging the issue,
and providing the patch.
https://www.open-mpi.org/community/lists/devel/2016/05/18918.php
(cherry picked from open-mpi/hwloc@0ab7af5e90)
instead of doing AC_CHECK_HEADERS+AC_CHECK_LIB and only using the result of the former.
Thanks to Paul Hargrove for reporting the issue (OMPI build with -m32).
(cherry picked from open-mpi/hwloc@9549fd59af)
setmntent() doesn't support root_fd, but manual parsing of
/proc/mounts is fragile, and actually buggy for very long mount lines
(see open-mpi/hwloc#142 (comment)).
Since we only openat("/proc/mounts") there, just manually concatenate
the fsroot_path and use setmntent().
Thanks to Nathan Hjelm for the report.
(Cherry-picked from open-mpi/hwloc@d2d07b9a22)
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>