* if the node does not access the stack frame or is no back-end node.
*
*/
-entity *be_get_frame_entity(ir_node *irn);
+entity *be_get_frame_entity(const ir_node *irn);
void be_set_Spill_entity(ir_node *irn, entity *ent);
-entity *be_get_spill_entity(ir_node *irn);
+entity *be_get_spill_entity(const ir_node *irn);
ir_node *be_get_Spill_context(const ir_node *irn);