ep_testsuite "mem stats" fails if CB_DEVELOPMENT_ASSERTS=OFF

bool CheckpointMemRecoveryTask::runInner() {

...

    case CheckpointRemoval::Eager: {

#if CB_DEVELOPMENT_ASSERTS

        // if eager checkpoint removal has been configured, calling

        // attemptCheckpointRemoval here should never, ever, find any

        // checkpoints to remove; they should always be removed as soon

        // as they are made eligible, before the lock is released.

        // This is not cheap to verify, as it requires scanning every

        // vbucket, so is only checked if dev asserts are on.

        Expects(attemptCheckpointRemoval().second == 0);

#endif

        break;

    }

CheckpointMemRecoveryTask::attemptCheckpointRemoval() {

...

memReleased +=

                vb->checkpointManager->removeClosedUnrefCheckpoints().memory;

CheckpointManager::ReleaseResult

CheckpointManager::removeClosedUnrefCheckpoints() {

...

    CheckpointList toRelease;

    {

        std::lock_guard<std::mutex> lh(queueLock);

        maybeCreateNewCheckpoint(lh);

        toRelease = extractClosedUnrefCheckpoints(lh);

    }

static enum test_result test_mem_stats(EngineIface* h) {

...

    int itemsRemoved = get_int_stat(h, "ep_items_rm_from_checkpoints");

    wait_for_persisted_value(h, "key", value.c_str());

    testHarness->time_travel(65);

    if (isPersistentBucket(h)) {

        wait_for_stat_change(h, "ep_items_rm_from_checkpoints", itemsRemoved);

    }