[RFAv2 3/3] NEWS and documentation for $_gdb_setting and $_gdb_int_setting.

[Eli Zaretskii]

> From: Philippe Waroquiers <philippe.waroquiers@skynet.be>
> Cc: gdb-patches@sourceware.org
> Date: Sat, 06 Jul 2019 12:54:39 +0200
> 
> > The last part begs a question how to know whether 'unlimited' will
> > yield zero or -1?  Can't we always return -1?
> I think it is better to keep the same convention as what is accepted
> by the "set" command: some settings are using 0 to mean unlimited
> and some are using -1.
> I have tried to describe this in the doc RFAv3.

The new text is OK, but I'd suggest to say in addition something like
"See the documentation of the corresponding @code{set} command for
the numerical value equivalent to @code{unlimited}."

> > Btw, do we have a way of determining whether a given convenience
> > function exists in the current GDB?  For variables, one can use
> > $_isvoid, I think, but what about functions?
> 
> I do not know of any way to see if a user defined function or convenience
> function is defined.
> For the GDB convenience function, the GDB major/minor can be used to 
> determine what is available.

OK, thanks.