bugfix:  now also supports Tuple nodes.
bugfix:  now also supports Tuple nodes.

[r6217]

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