pgsql: postgres_fdw: Attempt to stabilize regression results.

postgres_fdw: Attempt to stabilize regression results.

Set enable_hashagg to false for tests involving least_agg(), so that
we get the same plan regardless of local costing variances.  Also,
remove a test involving sqrt(); it's there to test deparsing of
HAVING clauses containing expressions, but that's tested elsewhere
anyway, and sqrt(2) deparses with different amounts of precision on
different machines.

Per buildfarm.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ad13a09d762f0c903a52ed0ec668a0ba51a61047

Modified Files
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contrib/postgres_fdw/expected/postgres_fdw.out | 74 ++++++++------------------
contrib/postgres_fdw/sql/postgres_fdw.sql      |  9 ++--
2 files changed, 25 insertions(+), 58 deletions(-)