Withdrawn, superseded by:
https://www.postgresql.org/message-id/PH0PR18MB444315CD3E17255AB4A629BEA6AD2%40PH0PR18MB4443.namprd18.prod.outlook.com
This patch converted a join at rewrite time. The new one builds a
second relation, carries it through the join search, and leaves the choice to
cost. It gets better plans than this one did too, in more cases.
Thanks for the review, Tom.
Will