ir_spec: Use new-style python classes.
ir_spec: Use new-style python classes.

Otherwise the jFirm binding generator has a hard time determining the
class hierarchies because there is no __base__ field.

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