mysql-test/r/derived.result:
  derived table bug test
mysql-test/t/derived.test:
  derived table bug test
sql/mysql_priv.h:
  new mysql_new_select call & layout fixing
sql/sql_class.h:
  passing unit as parameter of Table_ident constructor
sql/sql_lex.cc:
  new SELECT_LEX structure methods
sql/sql_lex.h:
  new SELECT_LEX structure definition
sql/table.h:
  fixed layout