MDEV-10139 Support for SEQUENCE objects

Working features:
CREATE OR REPLACE [TEMPORARY] SEQUENCE [IF NOT EXISTS] name
    [ INCREMENT [ BY | = ] increment ]
    [ MINVALUE [=] minvalue | NO MINVALUE ]
    [ MAXVALUE [=] maxvalue | NO MAXVALUE ]
    [ START [ WITH | = ] start ] [ CACHE [=] cache ] [ [ NO ] CYCLE ]
    ENGINE=xxx COMMENT=".."
SELECT NEXT VALUE FOR sequence_name;
SELECT NEXTVAL(sequence_name);
SELECT PREVIOUS VALUE FOR sequence_name;
SELECT LASTVAL(sequence_name);

SHOW CREATE SEQUENCE sequence_name;
SHOW CREATE TABLE sequence_name;
CREATE TABLE sequence-structure ... SEQUENCE=1
ALTER TABLE sequence RENAME TO sequence2;
RENAME TABLE sequence TO sequence2;
DROP [TEMPORARY] SEQUENCE  [IF EXISTS] sequence_names

Missing features
- SETVAL(value,sequence_name), to be used with replication.
- Check replication, including checking that sequence tables are marked
  not transactional.
- Check that a commit happens for NEXT VALUE that changes table data (may
  already work)
- ALTER SEQUENCE. ANSI SQL version of setval.
- Share identical sequence entries to not add things twice to table list.
- testing insert/delete/update/truncate/load data
- Run and fix Alibaba sequence tests (part of mysql-test/suite/sql_sequence)
- Write documentation for NEXT VALUE / PREVIOUS_VALUE
- NEXTVAL in DEFAULT
  - Ensure that NEXTVAL in DEFAULT uses database from base table
- Two NEXTVAL for same row should give same answer.
- Oracle syntax sequence_table.nextval, without any FOR or FROM.
- Sequence tables are treated as 'not read constant tables' by SELECT; Would
  be better if we would have a separate list for sequence tables so that
  select doesn't know about them, except if refereed to with FROM.

Other things done:
- Improved output for safemalloc backtrack
- frm_type_enum changed to Table_type
- Removed lex->is_view and replaced with lex->table_type. This allows
  use to more easy check if item is view, sequence or table.
- Added table flag HA_CAN_TABLES_WITHOUT_ROLLBACK, needed for handlers
  that want's to support sequences
- Added handler calls:
 - engine_name(), to simplify getting engine name for partition and sequences
 - update_first_row(), to be able to do efficient sequence implementations.
 - Made binlog_log_row() global to be able to call it from ha_sequence.cc
- Added handler variable: row_already_logged, to be able to flag that the
  changed row is already logging to replication log.
- Added CF_DB_CHANGE and CF_SCHEMA_CHANGE flags to simplify
  deny_updates_if_read_only_option()
- Added sp_add_cfetch() to avoid new conflicts in sql_yacc.yy
- Moved code for add_table_options() out from sql_show.cc::show_create_table()
- Added String::append_longlong() and used it in sql_show.cc to simplify code.
- Added extra option to dd_frm_type() and ha_table_exists to indicate if
  the table is a sequence. Needed by DROP SQUENCE to not drop a table.

sql/sql_base.cc

@@ -1934,6 +1934,11 @@ retry_share:
     DBUG_RETURN(true);
   }
 #endif
+  if (table_list->sequence && table->s->table_type != TABLE_TYPE_SEQUENCE)
+  {
+      my_error(ER_NOT_SEQUENCE, MYF(0), table_list->db, table_list->alias);
+      DBUG_RETURN(true);
+  }
 
   table->init(thd, table_list);
 
@@ -3650,8 +3655,9 @@ lock_table_names(THD *thd, const DDL_options_st &options,
     DBUG_RETURN(FALSE);
 
   /* Check if CREATE TABLE without REPLACE was used */
-  create_table= thd->lex->sql_command == SQLCOM_CREATE_TABLE &&
-                !options.or_replace();
+  create_table= ((thd->lex->sql_command == SQLCOM_CREATE_TABLE ||
+                  thd->lex->sql_command == SQLCOM_CREATE_SEQUENCE) &&
+                 !options.or_replace());
 
   if (!(flags & MYSQL_OPEN_SKIP_SCOPED_MDL_LOCK))
   {
@@ -4518,7 +4524,7 @@ TABLE *open_n_lock_single_table(THD *thd, TABLE_LIST *table_l,
   /* Set requested lock type. */
   table_l->lock_type= lock_type;
   /* Allow to open real tables only. */
-  table_l->required_type= FRMTYPE_TABLE;
+  table_l->required_type= TABLE_TYPE_NORMAL;
 
   /* Open the table. */
   if (open_and_lock_tables(thd, table_l, FALSE, flags,
@@ -4574,7 +4580,7 @@ TABLE *open_ltable(THD *thd, TABLE_LIST *table_list, thr_lock_type lock_type,
   THD_STAGE_INFO(thd, stage_opening_tables);
   thd->current_tablenr= 0;
   /* open_ltable can be used only for BASIC TABLEs */
-  table_list->required_type= FRMTYPE_TABLE;
+  table_list->required_type= TABLE_TYPE_NORMAL;
 
   /* This function can't properly handle requests for such metadata locks. */
   DBUG_ASSERT(table_list->mdl_request.type < MDL_SHARED_UPGRADABLE);
@@ -5602,6 +5608,13 @@ find_field_in_table_ref(THD *thd, TABLE_LIST *table_list,
          strcmp(db_name, table_list->db)))))
     DBUG_RETURN(0);
 
+  /*
+    Don't allow usage of fields in sequence table that is opened as part of
+    NEXT VALUE for sequence_name
+  */
+  if (table_list->sequence)
+    DBUG_RETURN(0);
+
   *actual_table= NULL;
 
   if (table_list->field_translation)