Re: Removing unneeded self joins

New version of the feature.
Here a minor bug with RowMarks is fixed. A degenerated case is fixed, 
when uniqueness of an inner deduced not from join quals, but from a 
baserestrictinfo clauses 'x=const', where x - unique field.
Code, dedicated to solve second issue is controversial, so i attached 
delta.txt for quick observation.
Maybe we should return to previous version of code, when we didn't split 
restriction list into join quals and base quals?

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Regards
Andrey Lepikhov
Postgres Professional