If check_quick_select returns non-empty range then the function cost_group_min_max
cannot return 0 as an estimate of the number of retrieved records.
Yet the function erroneously returned 0 as the estimate in some situations.


mysql-test/r/group_min_max.result:
  Added a test case for bug #16203.
mysql-test/t/group_min_max.test:
  Added a test case for bug #16203.