/** Remarks that edge pos is a backedge. */
void set_backedge (ir_node *n, int pos);
/** Remarks that edge pos is not a backedge. */
void set_not_backedge (ir_node *n, int pos);
/** Remarks that edge pos is a backedge. */
void set_backedge (ir_node *n, int pos);
/** Remarks that edge pos is not a backedge. */
void set_not_backedge (ir_node *n, int pos);