[COMMITTERS] pgsql: Improve regression test coverage for TID scanning.

Improve regression test coverage for TID scanning.

TidScan plan nodes were not systematically tested before.  These additions
raise the LOC coverage number for the basic regression tests from 52% to
92% in nodeTidscan.c, and from 60% to 93% in tidpath.c.

Andres Freund, tweaked a bit by me

Discussion: https://postgr.es/m/20170320062511.hp5qeurtxrwsvfxr@alap3.anarazel.de

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/be6c3d19fd454359f05176eb1add82d4fc6e7758

Modified Files
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src/test/regress/expected/tidscan.out | 179 ++++++++++++++++++++++++++++++++++
src/test/regress/parallel_schedule    |   2 +-
src/test/regress/serial_schedule      |   1 +
src/test/regress/sql/tidscan.sql      |  66 +++++++++++++
4 files changed, 247 insertions(+), 1 deletion(-)