fixes for gcc 4.0: void * and pointer to function are not compatible anymore
fixes for gcc 4.0: void * and pointer to function are not compatible anymore

[r6541]

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