HashAggregationOperator misreports memory usage after spilling #10596
Description
In some situations, when spilling occurs, HashAggregationOperator doesn't reset memory usage to 0 upon finishing.
Can be reproduced with io.trino.operator.TestHashAggregationOperator#testHashAggregationMemoryReservation
after adding assertions:
// this passes
assertEquals(getOnlyElement(operator.getOperatorContext().getNestedOperatorStats()).getRevocableMemoryReservation().toBytes(), 0);
// this fails in some cases:
assertEquals(getOnlyElement(operator.getOperatorContext().getNestedOperatorStats()).getSystemMemoryReservation().toBytes(), 0);right after
assertEquals(getOnlyElement(operator.getOperatorContext().getNestedOperatorStats()).getUserMemoryReservation().toBytes(), 0);cc @sopel39