regset -> regset_head in reload

[Bernd Schmidt]

> > 	* reload.h (struct insn_chain): Change live_throughout and dead_or_set
> > 	to be of type regset_head, not regset.  All users changed by adding
> > 	address operator.
> > 	* reload1.c (new_insn_chain): Don't allocate regsets, just clear them.
> 
> Ok I guess.
> 
> Do you notice any performance advantage?

I didn't try because I don't expect one.  It's going to save a couple of bytes
though.

Bernd