[RFA/NEWS] Document support for 64-bit core files on AIX

[Eli Zaretskii]

> Date: Fri, 18 Apr 2008 17:04:52 -0700
> From: Joel Brobecker <brobecker@adacore.com>
> 
> Thanks to Dennis, 64-bit core file support is now available in GDB.
> 
> 2008-04-18  Joel Brobecker  <brobecker@adacore.com>
> 
>         * NEWS: Document support for 64-bit core file.
> 
> OK to commit?

Yes, thanks.