pgsql: Reject currtid2() on unlogged tables during recovery.

Reject currtid2() on unlogged tables during recovery.

Commit 1e707d32564 made COPY TO report a proper error for unlogged
tables during recovery. currtid2() has the same problem: it reads the
table directly without going through the planner, so on a standby it
failed with a low-level error for an unlogged table:

ERROR: could not open file "base/5/16384": No such file or directory

Check for this case and report the same error as SELECT. No test is
added, as currtid2() is an undocumented internal function.

Backpatch to all supported versions, like commit 1e707d32564.

Reported-by: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
Author: Jim Jones <jim(dot)jones(at)uni-muenster(dot)de>
Discussion: https://postgr.es/m/CAD21AoDNa7pL760_23AN_wYPMkWXCt+Kw0_vJAcci4R5DoCQGg@mail.gmail.com
Backpatch-through: 14

Branch
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REL_15_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/7f641940c27b6be184951c01d8762194ca2ba779

Modified Files
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src/backend/utils/adt/tid.c | 7 +++++++
1 file changed, 7 insertions(+)