pgsql: Fix rare missing cancellations in Hot Standby.

Fix rare missing cancellations in Hot Standby.
The machinery around XLOG_HEAP2_CLEANUP_INFO failed
to correctly pass through the necessary information
on latestRemovedXid, avoiding cancellations in some
infrequent concurrent update/cleanup scenarios.

Backpatchable fix to 9.0

Detailed bug report and fix by Noah Misch,
backpatchable version by me.

Branch
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REL9_1_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/62b9e3a0ff2d9964e30635ceca825340e71087e1

Modified Files
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src/backend/access/heap/pruneheap.c |    2 +-
1 files changed, 1 insertions(+), 1 deletions(-)