Bump __FreeBSD_version for the addition of the following functions to libm:
  cacos, cacosf, cacosh, cacoshf,
  casin, casinf, casinh, casinhf,
  catan, catanf, catanh, catanhf,
  logl, log2l, log10l, log1pl
I am hoping kargl@ will commit expl and expm1l soon, in which case this
bump will cover those, too.

Requested by:	danfe