InnoDB: Implement fast TRUNCATE TABLE (Bug #7150)

innobase/dict/dict0boot.c:
  Added DICT_SYS_INDEXES_TYPE_FIELD
innobase/dict/dict0crea.c:
  Added dict_truncate_index_tree()
innobase/include/dict0boot.h:
  Added DICT_SYS_INDEXES_TYPE_FIELD
innobase/include/dict0crea.h:
  Added dict_truncate_index_tree()
innobase/include/row0mysql.h:
  Added row_truncate_table_for_mysql()
innobase/row/row0mysql.c:
  Added row_truncate_table_for_mysql()
sql/ha_innodb.cc:
  Added ha_innobase::delete_all_rows() in order to
  implement fast TRUNCATE TABLE
sql/ha_innodb.h:
  Added ha_innobase::delete_all_rows() in order to
  implement fast TRUNCATE TABLE