Day 6: add timed solve-day function

aoc20.lisp

@@ -231,3 +231,8 @@
   (length (mapcan (lambda (entry)
 		    (reduce #'intersection (map 'list (lambda (l) (coerce l 'list)) entry)))
 		  data)))
+
+(defun solve-6 (file)
+  (let ((data (read-6 file)))
+    (time (progn (print (solve-6-1 data))
+		 (print (solve-6-2 data))))))