[RFA/doco] Add index entry for command "set print frame-arguments"

[Joel Brobecker]

> > 2009-04-01  Joel Brobecker  <brobecker@adacore.com>
> > 
> >         * gdb.texinfo (Print Settings): Add kindex for command "set
> >         print frame-arguments".
> > 
> Yes, thanks.

Thanks! Checked in.

-- 
Joel