Support row and column aliases in INSERT ON DUPLICATE KEY UPDATE

[Hydrocharged]

Given the following example queries:

INSERT INTO t1 (a,b,c) VALUES (1,2,3),(4,5,6) AS new ON DUPLICATE KEY UPDATE c = new.a+new.b;
INSERT INTO t1 (a,b,c) VALUES (1,2,3),(4,5,6) AS new(m,n,p) ON DUPLICATE KEY UPDATE c = m+n;
INSERT INTO t1 SET a=1,b=2,c=3 AS new ON DUPLICATE KEY UPDATE c = new.a+new.b;
INSERT INTO t1 SET a=1,b=2,c=3 AS new(m,n,p) ON DUPLICATE KEY UPDATE c = m+n;

We currently do not support the AS new portion, which are the aliases.

Reference:
https://dev.mysql.com/doc/refman/8.0/en/insert-on-duplicate.html

[nicktobey]

This is a dupe of #7638, closing this one because the other issue has more context.