pthread_setspecific(3) on FreeBSD

The text 0ca2d2b73438, 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.

set a thread-specific data value

pthread_setspecific(3) on FreeBSD now