[PATCH 4/4] Document the new "-a" argument for gcore

[Eli Zaretskii]

> From: Sergio Lopez <slp@redhat.com>
> Cc: Sergio Lopez <slp@redhat.com>
> Date: Tue, 28 Nov 2017 14:21:48 +0100
> 
> +@item -a
> +Instruct GDB to unconditionally dump all sections (except IO), ignoring the
            ^^^
"@value{GDBN}"

> +value of @file{/proc/@var{pid}/coredump_filter} and the VM_DONTDUMP flag.

Is this Linux-specific?  Because AFAIK 'gcore' isn't, and so we need
to document that this switch and the details you've put into its
description are specific to Linux.

Also, VM_DONTDUMP should be in @code.

Thanks.