[patch] Forbid run with a core file loaded

[Eli Zaretskii]

> Date: Sun, 23 May 2010 20:54:40 +0200
> From: Jan Kratochvil <jan.kratochvil@redhat.com>
> Cc: gdb-patches@sourceware.org
> 
> +There are multiple classes of targets such as: processes, executable files or
> +recording sessions.  Core files belong to the process class, there can be
> +active only one of a core or a running process.

Something is wrong with the last sentence.