I configured the dingo and binturong Solaris 10 animals to build 9.3
some time ago but apparently they always failed the configure phase.
Turns out this is caused by thread_test's usage of sched_yield which is
in librt on Solaris but which is not pulled in by anything on 9.3 and
earlier on my box.
Apparently the other Solaris animal (castoroides) requires librt for
fdatasync, but that's not required on my system. On 9.4 and master
librt is required for shm_open so the check doesn't fail there.
Attached a patch to check for sched_yield in configure, the patch only
applies against 9.0 - 9.3 which are using autoconf 2.63. We should
probably check for sched_yield anyway on all branches even if it's not
strictly required on 9.4+ at the moment.
/ Oskari
