Allow safe x/y = x * (1.0/y) for exact 1.0/y even if floating point constant folding is disabled
Allow safe x/y = x * (1.0/y) for exact 1.0/y even if floating point constant folding is disabled

[r19653]

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