fixed new_tarval_from_long() (added missing sign extend), classify_tarval(), unsigned integer modes have minus_one_tarval()
fixed new_tarval_from_long() (added missing sign extend), classify_tarval(), unsigned integer modes have minus_one_tarval()

[r15391]

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