MDEV-28152 Features for sequences

- Add `as <int_type>` to sequence creation options
  - int_type can be signed or unsigned integer types, including
    tinyint, smallint, mediumint, int and bigint
  - Limitation: when alter sequence as <new_int_type>, cannot have any
    other alter options in the same statement
  - Limitation: increment remains signed longlong, and the hidden
    constraint (cache_size x abs(increment) < longlong_max) stays for
    unsigned types. This means for bigint unsigned, neither
    abs(increment) nor (cache_size x abs(increment)) can be between
    longlong_max and ulonglong_max
- Truncating maxvalue and minvalue from user input to the nearest max
  or min value of the type, plus or minus 1. When the truncation
  happens, a warning is emitted
- Information schema table for sequences

mysql-test/suite/sql_sequence/concurrent_create.test

@@ -77,3 +77,22 @@ COMMIT;
 # Cleanup
 DROP TABLE t1;
 DROP SEQUENCE s1;
+
+--echo #
+--echo # MDEV-28152 Features for sequence
+--echo #
+
+CREATE SEQUENCE s1 as mediumint unsigned ENGINE=InnoDB;
+PREPARE stmt FROM "CREATE TABLE s2 LIKE s1";
+execute stmt;
+drop table s2;
+execute stmt;
+show create sequence s2;
+drop table s2;
+execute stmt;
+select * from s2;
+DROP SEQUENCE s1, s2;
+
+--echo #
+--echo # End of 11.4 tests
+--echo #