[PATCH] Add FreeBSD/amd64

[Andrew Cagney]

> The attached adds a fully functional FreeBSD/amd64, both target and
> native.  I committed it to mainline.
> 
> I didn't add a NEWS entry yet.  If Andrew allows me, I'd like to check
> this in to the 6.0 branch too.  Since that would mean the entry would
> need to be added to a different section, I postponed it.

Yes, it's ok.  Can't break any core functionality.

Andrew