[PATCH] Implement new `info core mappings' command

[Eli Zaretskii]

> From: Sergio Durigan Junior <sergiodj@redhat.com>
> Cc: gdb-patches@sourceware.org
> Date: Thu, 03 Nov 2011 18:00:39 -0200
> 
> +It displays the memory
> +  regions in a corefile, similar to `info proc mappings' command.

Bad formatting.

Otherwise, fine with me.