Bitset added to pbqp_co_t data structure.

Bitset contain's information if node has register constraints or not

[r26660]

ir/be/becopypbqp.h

@@ -26,6 +26,7 @@ struct _pbqp_co_t {
 	pmap *map;							// contains relation between irn and pbqp node
 	pbqp *pbqp;
 	bitset_t *ignore_reg;
+	bitset_t *constatNodes;
 	be_ifg_t *ifg;
 };