Log Message:
-----------
Add code to eval_const_expressions() to support const-simplification of
CoerceViaIO nodes. This improves the ability of the planner to deal with
cases where the node input is a constant. Per bug #4170.
Modified Files:
--------------
pgsql/src/backend/optimizer/util:
clauses.c (r1.258 -> r1.259)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/util/clauses.c?r1=1.258&r2=1.259)