constbits: Always analyse normal (non-X, non-Phi) nodes, even if their block is unreachable.
constbits: Always analyse normal (non-X, non-Phi) nodes, even if their block is unreachable.

Unanalysable nodes never get triggered again, if their block gets reachable.
So this bottom information causes wrong results at other nodes.

This does not make the overall result worse, because Phis correctly consider only inputs, whose control flow edge is taken, and X nodes consider reachability of their block.

This corrects opt/fehler289.c.

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