MDEV-18468 merge instant_varchar_enlarge.test and alter_varchar_change.test

mysql-test/suite/innodb/r/alter_varchar_change.result

@@ -459,3 +459,12 @@ t1	CREATE TABLE `t1` (
 DROP TABLE t1;
 DROP PROCEDURE get_index_id;
 DROP PROCEDURE get_table_id;
+create table t (a varchar(100)) engine=innodb;
+select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
+name	pos	mtype	prtype	len
+a	0	1	524303	100
+alter table t modify a varchar(110), algorithm=inplace;
+select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
+name	pos	mtype	prtype	len
+a	0	1	524303	110
+drop table t;

mysql-test/suite/innodb/r/instant_varchar_enlarge.result

-create table t (a varchar(100)) engine=innodb;
-select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
-name	pos	mtype	prtype	len
-a	0	1	524303	100
-alter table t modify a varchar(110), algorithm=inplace;
-select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
-name	pos	mtype	prtype	len
-a	0	1	524303	110
-drop table t;

mysql-test/suite/innodb/t/alter_varchar_change.test

@@ -334,3 +334,10 @@ DROP TABLE t1;
 
 DROP PROCEDURE get_index_id;
 DROP PROCEDURE get_table_id;
+
+# LEN must increase here
+create table t (a varchar(100)) engine=innodb;
+select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
+alter table t modify a varchar(110), algorithm=inplace;
+select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
+drop table t;

mysql-test/suite/innodb/t/instant_varchar_enlarge.test

---source include/have_innodb.inc
-
-# LEN must increase here
-create table t (a varchar(100)) engine=innodb;
-select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
-alter table t modify a varchar(110), algorithm=inplace;
-select name, pos, mtype, prtype, len from information_schema.innodb_sys_columns where name='a';
-drop table t;