Remove obsolete Solaris 8 support

[Mike Stump]

On Mar 12, 2012, at 10:44 AM, Rainer Orth wrote:
> Since even extended support for Solaris 8 ends by March 31st, this patch
> removes Solaris 8 support from mainline.

One of the nice things about gcc is that gcc usually still works, long after a vendor has abandoned a machine.  I rather like that gcc will just work, unlike vendor software, which often says, please buy a new machine.  One doesn't have to remove support in gcc for something, just because a vendor doesn't support it.  That said, truly crufty things, should go.