asinf(3) on FreeBSD

The text c9068c4b64b0, as FreeBSD 2.2.8-RELEASE, FreeBSD 2.2.7-RELEASE, FreeBSD 2.2.6-RELEASE, FreeBSD 2.2.5-RELEASE, FreeBSD 2.2.2-RELEASE shipped it.

arc sine functions

asinf(3) on FreeBSD now