ada: Restore parent link for both lists and nodes in class-wide condition

ada: Restore parent link for both lists and nodes in class-wide condition

When preanalysing class-wide conditions, we restore "Function (Object)"
to its original "Object.Function" notation. This requires the Parent
links to be fixed. We did it for nodes; now we do it for lists as well.

This patch is enough to fix assertion failure in CCG and to make the
tree well-connected. Perhaps there is a more elegant solution, but that
remains to be investigated.

gcc/ada/

	* contracts.adb (Fix_Parent): Fir part both for lists and nodes.