Remove XtraDB

The XtraDB storage engine was already replaced by InnoDB
and disabled in MariaDB Server 10.2. Let us remove it altogether
to avoid dragging dead code around.

Replace some references to XtraDB with references to InnoDB.

rpl_get_position_info(): Remove.

Remove the mysql-test-run --suite=percona, because it only contains
tests specific to XtraDB, many of which were disabled already in
earlier MariaDB versions.

mysql-test/include/have_innodb.combinations

@@ -18,36 +18,6 @@ innodb-sys-tables
 innodb-sys-virtual
 innodb-metrics
 
-[xtradb_plugin]
-ignore-builtin-innodb
-plugin-load-add=$HA_XTRADB_SO
-innodb
-innodb-cmpmem
-innodb-cmp-per-index
-innodb-trx
-innodb-locks
-innodb-buffer-pool-stats
-innodb-buffer-page
-innodb-buffer-page-lru
-innodb-sys-foreign
-innodb-sys-foreign-cols
-innodb-sys-tables
-innodb-metrics
-
-[xtradb]
-innodb
-innodb-cmpmem
-innodb-cmp-per-index
-innodb-trx
-innodb-locks
-innodb-metrics
-innodb-buffer-pool-stats
-innodb-buffer-page
-innodb-buffer-page-lru
-innodb-sys-foreign
-innodb-sys-foreign-cols
-innodb-sys-tables
-
 [innodb]
 innodb
 innodb-cmpmem

mysql-test/include/have_innodb.inc

@@ -1,6 +1,6 @@
 #
 # suite.pm will make sure that all tests including this file
-# will be skipped unless innodb or xtradb is enabled
+# will be skipped unless innodb is enabled
 #
 # The test below is redundant
 

mysql-test/include/have_not_innodb_plugin.inc

@@ -1,4 +0,0 @@
-disable_query_log;
---require r/not_true.require
-select (PLUGIN_LIBRARY LIKE 'ha_innodb_plugin%' OR PLUGIN_DESCRIPTION LIKE '%xtradb%') as `TRUE` from information_schema.plugins where PLUGIN_NAME='InnoDB';
-enable_query_log;

mysql-test/include/have_xtradb.combinations

@@ -1,13 +0,0 @@
-[xtradb_plugin]
-ignore-builtin-innodb
-plugin-load-add=$HA_XTRADB_SO
-innodb
-innodb-cmpmem
-innodb-trx
-innodb-sys-indexes
-
-[xtradb]
-innodb
-innodb-cmpmem
-innodb-trx
-innodb-sys-indexes

mysql-test/include/have_xtradb.inc

@@ -1,11 +0,0 @@
-#
-# suite.pm will make sure that all tests including this file
-# will be skipped unless xtradb is enabled
-#
-# The test below is redundant
-
-if (!`SELECT count(*) FROM information_schema.plugins WHERE
-      plugin_name = 'innodb' AND plugin_status = 'active' AND
-      plugin_description LIKE '%xtradb%'`){
-  skip Needs XtraDB engine;
-}