pgsql: Fix brain fade in join-removal patch: a pushed-down clause in the

Log Message:
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Fix brain fade in join-removal patch: a pushed-down clause in the outer join's
restrict list is not just something to ignore, it's actually grounds to
abandon the optimization entirely.  Per bug #5255 from Matteo Beccati.

Modified Files:
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    pgsql/src/backend/optimizer/path:
        joinpath.c (r1.126 -> r1.127)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/joinpath.c?r1=1.126&r2=1.127)