[m-dev.] for review: fix MR_LOWLEVEL_DEBUG

[Zoltan Somogyi]

> > +#define	MR_CONTEXT(x)		MR_ENGINE(context).x
> > +
> 
> A comment may be helpful here.

I have added one above, both for MR_CONTEXT and for MR_ENGINE.

> > -	for (fr = maxfr; fr > nondetstack_zone->min; fr = bt_prevfr(fr)) {
> > +	for (fr = maxfr; fr > MR_CONTEXT(nondetstack_zone)->min;
> 
> Should that be MR_maxfr rather than maxfr?

Yes, but that is a separate change. Fergus tells me he has been waiting
for you to commit your threading changes to the runtime before he makes it :-)

Zoltan.