Added convenience macros for pset creation and introduced default pointer comparison function.
Added convenience macros for pset creation and introduced default
pointer comparison function.

[r4596]

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