irg_walk_graph(irg, firm_clear_link, link_ops_in_block_walker, NULL);
assert(env->stack_order == NULL);
env->stack_order = new_phase(irg, phase_irn_init_default);
irg_walk_graph(irg, firm_clear_link, link_ops_in_block_walker, NULL);
assert(env->stack_order == NULL);
env->stack_order = new_phase(irg, phase_irn_init_default);