Use repalloc_huge() to enlarge a SPITupleTable's tuple pointer array.

Commit 23a27b03 widened the rows-stored counters to uint64, but
that's academic unless we allow the tuple pointer array to exceed 1GB.

(It might be a good idea to provide some other limit on how much storage
a SPITupleTable can eat.  On the other hand, there are plenty of other
ways to drive a backend into swap hell.)

Dagfinn Ilmari Mannsåker

src/backend/executor/spi.c

@@ -1800,7 +1800,7 @@ spi_printtup(TupleTableSlot *slot, DestReceiver *self)
 		/* Double the size of the pointer array */
 		tuptable->free = tuptable->alloced;
 		tuptable->alloced += tuptable->free;
-		tuptable->vals = (HeapTuple *) repalloc(tuptable->vals,
+		tuptable->vals = (HeapTuple *) repalloc_huge(tuptable->vals,
 									  tuptable->alloced * sizeof(HeapTuple));
 	}