pgsql: Add HOLD_INTERRUPTS section into FinishPreparedTransaction.

Add HOLD_INTERRUPTS section into FinishPreparedTransaction.

If an interrupt arrives in the middle of FinishPreparedTransaction
and any callback decide to call CHECK_FOR_INTERRUPTS (e.g.
RemoveTwoPhaseFile can write a warning with ereport, which checks for
interrupts) then it's possible to leave current GXact undeleted.

Backpatch to all supported branches

Stas Kelvich

Discussion: ihttps://www.postgresql.org/message-id/3AD85097-A3F3-4EBA-99BD-C38EDF8D2949@postgrespro.ru

Branch
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REL9_4_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/6bd659f19cac6bcf7235ac4f7dd4e36c8d2cc755

Modified Files
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src/backend/access/transam/twophase.c | 5 +++++
1 file changed, 5 insertions(+)