optimization of left expression evaluation
more descriptive method name


mysql-test/r/func_in.result:
  test of _NEW_ IN behaviour with NULL
mysql-test/r/subselect.result:
  test of _NEW_ IN/ALL/ANY/SOME behaviour with NULL
mysql-test/t/func_in.test:
  test of _NEW_ IN behaviour with NULL
mysql-test/t/subselect.test:
  test of _NEW_ IN/ALL/ANY/SOME behaviour with NULL
sql/item.cc:
  _NEW_ IN/ALL/ANY/SOME behaviour with NULL
  optimization of left expression evaluation
sql/item.h:
  _NEW_ IN/ALL/ANY/SOME behaviour with NULL
  optimization of left expression evaluation
sql/item_cmpfunc.cc:
  _NEW_ IN/ALL/ANY/SOME behaviour with NULL
  optimization of left expression evaluation
sql/item_cmpfunc.h:
  _NEW_ IN/ALL/ANY/SOME behaviour with NULL
  optimization of left expression evaluation
sql/item_subselect.cc:
  _NEW_ IN/ALL/ANY/SOME behaviour with NULL
  optimization of left expression evaluation
sql/item_subselect.h:
  _NEW_ IN/ALL/ANY/SOME behaviour with NULL
  optimization of left expression evaluation
sql/sql_class.cc:
  more descriptive method name
sql/sql_union.cc:
  more descriptive method name