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.

mysql-test/suite/compat/oracle/r/sequence.result

@@ -0,0 +1,60 @@
+SET sql_mode=ORACLE;
+CREATE SEQUENCE s1;
+SHOW CREATE SEQUENCE s1;
+Table	Create Table
+s1	CREATE SEQUENCE "s1" start with 1 minvalue 1 maxvalue 9223372036854775806 increment by 1 cache 1000 nocycle
+SELECT s1.currval;
+s1.currval
+NULL
+SELECT s1.nextval;
+s1.nextval
+1
+SELECT s1.nextval;
+s1.nextval
+2
+SELECT s1.nextval;
+s1.nextval
+3
+EXPLAIN EXTENDED SELECT s1.nextval;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select nextval("test"."s1") AS "s1.nextval"
+SELECT nextval(s1);
+nextval(s1)
+4
+EXPLAIN EXTENDED SELECT s1.currval;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select lastval("test"."s1") AS "s1.currval"
+SELECT lastval(s1);
+lastval(s1)
+4
+DROP SEQUENCE s1;
+CREATE SEQUENCE s1;
+CREATE VIEW v1 AS SELECT s1.nextval AS a;
+SELECT VIEW_DEFINITION FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME='v1';
+VIEW_DEFINITION
+select nextval(`test`.`s1`) AS `a`
+SELECT * FROM v1;
+a
+1
+SHOW CREATE VIEW v1;
+View	Create View	character_set_client	collation_connection
+v1	CREATE VIEW "v1" AS select nextval("test"."s1") AS "a"	latin1	latin1_swedish_ci
+DROP VIEW v1;
+DROP SEQUENCE s1;
+CREATE SEQUENCE s1;
+CREATE VIEW v1 AS SELECT s1.currval AS a;
+SELECT VIEW_DEFINITION FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME='v1';
+VIEW_DEFINITION
+select lastval(`test`.`s1`) AS `a`
+SELECT * FROM v1;
+a
+NULL
+SHOW CREATE VIEW v1;
+View	Create View	character_set_client	collation_connection
+v1	CREATE VIEW "v1" AS select lastval("test"."s1") AS "a"	latin1	latin1_swedish_ci
+DROP VIEW v1;
+DROP SEQUENCE s1;