[RFA] Constify find_condition_and_thread

[Eli Zaretskii]

> From: Tom Tromey <tromey@redhat.com>
> Cc: Eli Zaretskii <eliz@gnu.org>, Keith Seitz <keiths@redhat.com>,        gdb-patches@sourceware.org
> Date: Fri, 01 Mar 2013 12:33:46 -0700
> 
> I think the problem is that the parsers probably do modify the input
> string.  So, you couldn't pass in a readonly string.

I figured that much.  But if that's the problem, perhaps the caller
should xstrdup the original string and pass a modifiable one to its
callees, instead of forcing low-level subroutines do that.