Added stuff to allow multiple move VOPs per SC pair, with selection ebing
done by the primitive type of the operands. Also, added stuff to delete moves to :NORMAL TNs that have no reads. Changed the existing special-casing of unread results to only punt on :NORMAL TNs. Also, fixed the move/coerce generation stuff to just leave alone the MOVEs that are o.k., instead of deleting the old MOVE and inserting a new one.