flag day for Solaris portions of config.{guess,sub}

[Ben Elliston]

Paul Eggert has been asking over the course of the last year when
config.{guess,sub} will start to correctly identify Solaris version
numbers.  The problem is that config.guess misidentifies Solaris 7, 8,
and 9, and it will probably misidentify Solaris 10 (unless Sun
marketing changes Solaris names again).  For example, on a Solaris 8
box, config.guess outputs "sparc-sun-solaris2.8"; but there never was
and never will be a "Solaris 2.8", as Solaris 2.6 (SunOS 5.6) was
immediately followed by Solaris 7 (SunOS 5.7).

The time to fix this is now long overdue.  Before I do, I want to give
plenty of warning to the GNU packages that comprise the toolchain, as
these are typically most sensitive to the output of config.guess.  Any
objections?  I have documented the change in a new config/NEWS file
that is already committed to subversions.gnu.org.

Ben