post-merge: --ps-protocol fixes

Includes:

MDEV-17302 Add support for ALTER USER command in prepared statement

and

MDEV-17673 main.cte_recursive fails in bb-10.4-ps branch in --ps

  Set correct SELECT_LEX linkage for recursive CTEs.
  Do not delegate this job to TABLE_LIST::set_as_with_table,
  because it is only run on prepare, while With_element::move_anchors_ahead
  is run both on prepare and execute (fix by Igor)

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

@@ -1166,7 +1166,9 @@ DROP TABLE t;
 CREATE TABLE t (a INT) ENGINE=INNODB;
 -- remove_file $MYSQL_DATA_DIR/test/t.frm
 -- move_file $MYSQL_DATA_DIR/test/t.fr_ $MYSQL_DATA_DIR/test/t.frm
+--enable_prepare_warnings
 SHOW CREATE TABLE t;
+--disable_prepare_warnings
 DROP TABLE t;
 
 --disable_query_log