Added a teast case for bug #11284.
sql_select.cc:
  Fixed bug #11284.
  Optimization with empty inner table currently cannot be
  used in the case of nested outer join.


sql/sql_select.cc:
  Fixed bug #11284.
  Optimization with empty inner table currently cannot be
  used in the case of nested outer join.
mysql-test/t/join_nested.test:
  Added a teast case for bug #11284.