pgsql: Reinstate tests accidentally removed by e3fcca0d0d

Reinstate tests accidentally removed by e3fcca0d0d

Commit e3fcca0d0d24 reverted modifications to HOT for BRIN, but it also
removed a couple unrelated tests from stats.sql. Reinstate those tests.

Reported-by: Peter Eisentraut

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/0df4eb3f708626ba3b0fdfab5afccf785e5e945c

Modified Files
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src/test/regress/expected/stats.out | 242 ++++++++++++++++++++++++++++++++++++
src/test/regress/sql/stats.sql      | 111 +++++++++++++++++
2 files changed, 353 insertions(+)