pgsql: Fix failure to mark all aggregates with appropriate transtype.

Fix failure to mark all aggregates with appropriate transtype.

In commit 915b703e1 I gave get_agg_clause_costs() the responsibility of
marking Aggref nodes with the appropriate aggtranstype. I failed to notice
that where it was being called from, it might see only a subset of the
Aggref nodes that were in the original targetlist. Specifically, if there
are duplicate aggregate calls in the tlist, either make_sort_input_target
or make_window_input_target might put just a single instance into the
grouping_target, and then only that instance would get marked. Fix by
moving the call back into grouping_planner(), before we start building
assorted PathTargets from the query tlist. Per report from Stefan Huehner.

Report: <20160702131056(dot)GD3165(at)huehner(dot)biz>

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/420c1661630c96ad10f58ca967d5f561bb404cf9

Modified Files
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src/backend/optimizer/plan/planner.c | 54 ++++++++++++++++++++++--------------
src/test/regress/expected/limit.out | 24 ++++++++++++++++
src/test/regress/sql/limit.sql | 8 ++++++
3 files changed, 65 insertions(+), 21 deletions(-)