Multi-arch only GDB 6.0 ....

[Andrew Cagney <ac131313@cygnus.com>]

So,

The GDB 5.0 version bump came about mainly because:

	o	5.0 requires an ISO C compiler

If someone wants to build GDB using a K&R compiler, they could use the 
older 4.x series or a ISO->K&R converter.  (It also was part of moving 
GDB to a public repository but that is secondary).

I think it is time to think about a GDB version bump.  This time the 
reason being (credit to Martin Hunt):

	o	6.0 only supports multi-arch targets

If someone wants to use GDB on an older more obscure target then they 
can grab an old 5.x release.

A tentative schedule (based on this 4 month release cycle) would be:

	jul-aug: 5.3 mark all as obsolete
	nov-dec: 6.0 have removed them (YA!)
	
Anyway, I'm going to mention all these going to be obsoleted targets in 
5.2's NEWS file.

Thoughts?
Andrew