msun: Correct FreeBSD version in sincos() man page

[brad_comstyle.com]

Summary

The sincos() man page notes the function was added to msun in FreeBSD 9.0 which must have been an oversight in the review as it was commited to 12.0 and then backported to the 11 branch.

So I have provided a diff to correct this to the first FreeBSD version it did ship with which was 11.2.

[dim]

Yeah, I think Steve Kargl actually implemented it in the 9.0 timeframe but only submitted it much later. It's probably good to fixup the history here.

[imp]

In D40308#921651, @dim wrote:

Yeah, I think Steve Kargl actually implemented it in the 9.0 timeframe but only submitted it much later. It's probably good to fixup the history he

IIRC too, someone, I forget who, put together a bunch of long double support by hackily converting to double, using the double routines, then converting back to get a 'good enough' half-assed answer... I can't recall if that was committed in the 9.x time frame (it may have been) and then removed sometime 11ish when real support came in. I don't think these functions were on the list, though.