Fix emit_insn_before_setloc

[Jan Hubicka]

> On 3/17/07, Jan Hubicka <jh@suse.cz> wrote:
> >Hi,
> >emit_insn_before_setloc ICE when called on very first instruction.  This
> >happens with my patch to remove some useless INSN notes.
> >
> >Bootstrapped/regtested i686-linux, OK?
> 
> This looks obviously small - so you might apply this if you think it is ok.

It is needed mainly for the followup patch to kill line number notes,
but I've comitted it now, since it can make life slightly easier
otherwise as well.

Thanks,
Honza
> 
> Thanks,
> Richard.
> 
> >Honza
> >
> >        * emit-rtl.c (emit_insn_before_setloc): Do not ICE when asked to 
> >        emit
> >        before very first instruction.