fn normalize_ite_args(f: NodeID, g: NodeID, h: NodeID) -> (NodeID, NodeID, NodeID)
Bring ITE calls of the form ite(f,f,h) = ite(f,1,h) = ite(h,1,f) ite(f,g,f) = ite(f,g,0) = ite(g,f,0) into canonical form
