[mkantautas]

Fixes #1005

In the MySQL dialect, FOR UPDATE was not a reserved clause, so UPDATE was formatted as the start of a new clause:

WHERE
  id = ? FOR
UPDATE;

This adds FOR UPDATE to the MySQL reserved clauses, as PostgreSQL and PL/SQL already do, so the output becomes:

WHERE
  id = ?
FOR UPDATE;

The new test in test/mysql.test.ts covers FOR UPDATE and FOR UPDATE SKIP LOCKED; it fails without the change.

[nene]

I'm adopting a new policy for this repository: no AI-generated contributions. I don't care how good they are.

This is to preserve my sanity.