Log Message:
-----------
Teach eval_const_expressions to simplify BooleanTest nodes that have
constant input. Seems worth doing because rule rewriter inserts
IS NOT TRUE tests into WHERE clauses.
Modified Files:
--------------
pgsql/src/backend/optimizer/util:
clauses.c (r1.216 -> r1.217)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/util/clauses.c.diff?r1=1.216&r2=1.217)