Bug #26370 Multi-table delete does not work across databases

Description:
Joining tables across different schema's for deletion purposes causes MySQL to barf.

How to repeat:
CREATE DATABASE db1;
CREATE DATABASE db2;

USE db1;

CREATE TABLE `db1`.`t1` (
  `a` INT NOT NULL,
  `b` INT,
  PRIMARY KEY (`a`)
)
CHARACTER SET utf8;

CREATE TABLE `db2`.`t2` (
  `a` INT NOT NULL,
  `c` INT,
  PRIMARY KEY (`a`)
)
CHARACTER SET utf8;

Insert into db1.t1 (a,b) VALUES(1,1);
Insert into db2.t2 (a,c) VALUES(1,2);

Delete x,y from db1.t1 x Inner Join db2.t2 y on x.a = y.a Where x.a=1;

DROP TABLE db1.t1;
DROP TABLE db2.t2;

DROP DATABASE db1;
DROP DATABASE db2;

Suggested fix:
Make it so this works.

This is a MySQL server issue, not a Merlin issue.

Please do not submit the same bug more than once. An existing bug report already describes this very problem. Even if you feel that your issue is somewhat different, the resolution is likely
to be the same. Because of this, we hope you add your comments to the original bug instead.

Thank you for your interest in MySQL.

Duplicate of Bug #23413