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.

sql/log_event.cc

@@ -14001,43 +14001,6 @@ Heartbeat_log_event::Heartbeat_log_event(const char* buf, uint event_len,
 #endif
 
 #if defined(MYSQL_SERVER)
-/*
-  Access to the current replication position.
-
-  There is a dummy replacement for this in the embedded library that returns
-  FALSE; this is used by XtraDB to allow it to access replication stuff while
-  still being able to use the same plugin in both stand-alone and embedded.
-
-  In this function it's ok to use active_mi, as this is only called for
-  the main replication server.
-*/
-bool rpl_get_position_info(const char **log_file_name, ulonglong *log_pos,
-                           const char **group_relay_log_name,
-                           ulonglong *relay_log_pos)
-{
-#if defined(EMBEDDED_LIBRARY) || !defined(HAVE_REPLICATION)
-  return FALSE;
-#else
-  const Relay_log_info *rli= &(active_mi->rli);
-  if (!rli->mi->using_parallel())
-  {
-    *log_file_name= rli->group_master_log_name;
-    *log_pos= rli->group_master_log_pos +
-      (rli->future_event_relay_log_pos - rli->group_relay_log_pos);
-    *group_relay_log_name= rli->group_relay_log_name;
-    *relay_log_pos= rli->future_event_relay_log_pos;
-  }
-  else
-  {
-    *log_file_name= "";
-    *log_pos= 0;
-    *group_relay_log_name= "";
-    *relay_log_pos= 0;
-  }
-  return TRUE;
-#endif
-}
-
 /**
    Check if we should write event to the relay log