[RFA] Fix some gdb.ada tests failures due to naming conflict.

[Philippe Waroquiers]

On Mon, 2018-12-24 at 13:58 -0700, Tom Tromey wrote:
> > > > > > "Philippe" == Philippe Waroquiers <philippe.waroquiers@skynet.be> writes:
> > > FAIL: gdb.ada/rename_subscript_param.exp: print b before changing its value (timeout)
> 
> Note that this particular one is PR ada/23381, so that should be
> mentioned in the ChangeLog.
Ouch, I forgot to add this in the RFAv2 ChangeLog.
I will add this before pushing.
Philippe