pgsql: Fix HeapTupleSatisfiesVacuum on aborted updater xacts

Fix HeapTupleSatisfiesVacuum on aborted updater xacts

By using only the macro that checks infomask bits
HEAP_XMAX_IS_LOCKED_ONLY to verify whether a multixact is not an
updater, and not the full HeapTupleHeaderIsOnlyLocked, it would come to
the wrong result in case of a multixact containing an aborted update;
therefore returning the wrong result code.  This would cause predicate.c
to break completely (as in bug report #8273 from David Leverton), and
certain index builds would misbehave.  As far as I can tell, other
callers of the bogus routine would make harmless mistakes or not be
affected by the difference at all; so this was a pretty narrow case.

Also, no other user of the HEAP_XMAX_IS_LOCKED_ONLY macro is as
careless; they all check specifically for the HEAP_XMAX_IS_MULTI case,
and they all verify whether the updater is InvalidXid before concluding
that it's a valid updater.  So there doesn't seem to be any similar bug.

Branch
------
REL9_3_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/0b3859f3b607b375cfabb0a95bb4c58a4c1b37ee

Modified Files
--------------
src/backend/utils/time/tqual.c |    4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)