bespill: Remove strange mode_is_data() checks.
bespill: Remove strange mode_is_data() checks.

When there is a must_be_different constraint, it must be handled.
The mode of the value should not influence this.
This was some very old code.

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