RFA: Patch: implement missing macro functions

[Eli Zaretskii]

> Cc: gdb-patches@sourceware.org
> From: Tom Tromey <tromey@redhat.com>
> Date: Fri, 23 May 2008 14:28:32 -0600
> 
> +This command only affects definitions provided with the @command{macro
> +define} command, described above; it cannot remove definitions present
> +in the program being debugged.

We use @code for GDB commands, not @command.  (Yes, I know it was like
that in the original text.)  Other than that, the patch for the manual
is fine with me.

Btw, I think these new commands deserve a NEWS entry.

Thanks.