new_Block should not set curr_block too

[r24610]

ir/ir/ircons.c

@@ -1774,7 +1774,6 @@ new_d_Block(dbg_info *db, int arity, ir_node **in) {
 		}
 
 	if (!has_unknown) res = optimize_node(res);
-	current_ir_graph->current_block = res;
 
 	IRN_VRFY_IRG(res, current_ir_graph);