ia32: split peephole opts into 2 passes
ia32: split peephole opts into 2 passes

Some peephole optimisations enable others, so splitting into multiple
passes makes sense.

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