fix dwarf abbrev registration
fix dwarf abbrev registration

apparently abbrev number 0 is not allowed, so we have to start our
abbrev numbers at 1

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