spill: Correct remat_count.
spill: Correct remat_count.

Rematerialisations involving multiple nodes and Projs (e.g. Proj->Load) got miscounted.
Now a rematerialization always counts as 1.

davidgiven/libfirm,davidgiven/libfirm,jonashaag/libfirm,libfirm/libfirm,killbug2004/libfirm,davidgiven/libfirm,jonashaag/libfirm,8l/libfirm,davidgiven/libfirm,killbug2004/libfirm,davidgiven/libfirm,MatzeB/libfirm,jonashaag/libfirm,killbug2004/libfirm,MatzeB/libfirm,jonashaag/libfirm,MatzeB/libfirm,MatzeB/libfirm,MatzeB/libfirm,8l/libfirm,libfirm/libfirm,libfirm/libfirm,killbug2004/libfirm,killbug2004/libfirm,8l/libfirm,davidgiven/libfirm,jonashaag/libfirm,8l/libfirm,MatzeB/libfirm,8l/libfirm,jonashaag/libfirm,libfirm/libfirm,8l/libfirm,davidgiven/libfirm,libfirm/libfirm,MatzeB/libfirm,jonashaag/libfirm,killbug2004/libfirm,8l/libfirm,killbug2004/libfirm