pthread_exit(3) on FreeBSD

The text e40410d72405, as FreeBSD 3.2-RELEASE, FreeBSD 3.1-RELEASE, FreeBSD 3.0-RELEASE, FreeBSD 2.2.9-RELEASE, FreeBSD 2.2.8-RELEASE shipped it.

terminate the calling thread

pthread_exit(3) on FreeBSD now