The first node of the max independent set is always the root node.

becopyopt: Inline the thin wrapper nodes_interfere(), so we do not need to fetch the liveness info over and over again.

There is not (middleend) Start node in a graph at this point.

This also allowed us to get rid of an unnecessary exception in
verify_Proj_Proj()

Just state the copyright and the project the files belong to. You can
then find the COPYING file for the whole project.

The global type is final, so the next test bails out.

Accordingly remove repr_class from entities.

(This really shouldn't be allowed but until lower_calls is fixed this
should at least get complex working on sparc/arm)

In particular this ensures that the backend has segments for the PIC symbols and trampolines.