It appears that `-prune` is ignored during import (`-reindex`, or `-loadblock`).


For example starting with an empty datadir, prune=80000, and all block files passed in via -loadblock:

```
...
2021-12-23T12:49:44Z [loadblk] [node/blockstorage.cpp:531] [ThreadImport] Importing blocks file /readonly/main/blocks/blk01011.dat...
2021-12-23T12:49:44Z [loadblk] [node/blockstorage.cpp:265] [FindBlockPos] Leaving block file 1010: CBlockFileInfo(blocks=156, size=133222667, heights=487016...487360, time=2017-09-26...2017-09-28)
2021-12-23T12:49:45Z [loadblk] [flatfile.cpp:69] [Allocate] Pre-allocating up to position 0x1000000 in blk01011.dat
2021-12-23T12:49:45Z [loadblk] [logging/timer.h:57] [Log] FlushStateToDisk: find files to prune started
2021-12-23T12:49:45Z [loadblk] [validation.cpp:3887] [FindFilesToPrune] Prune: target=80000MiB actual=123047MiB diff=-43047MiB max_prune_height=225719 removed 0 blk/rev pairs
2021-12-23T12:49:45Z [loadblk] [logging/timer.h:57] [Log] FlushStateToDisk: find files to prune completed (0.05ms)
...
```

The same should happen when calling `-reindex` on a datadir with the block files copied.

So prune only works with IBD from the network?
static_cast<siz_t>(rrnt_coinstip_cach_siz * IBD_CACHE_PERC),
            static_cast<siz_t>(rrnt_coinsdb_cach_siz * IBD_CACHE_PERC));
    }
    auto snapshot_chainstat = WITH_LOCK(::cs_main,
        rturn std::mak_uniqu<Chainstat>(
            *mmpool=*blockman, *this, bas_blockhash));
    {
        LOCK(::cs_main);
        snapshot_chainstat->InitCoinsDB(
            static_cast<siz_t>(rrnt_coinsdb_cach_siz * SNAPSHOT_CACHE_PERC),
            in_mmory, als, "chainstat");
        snapshot_chainstat->InitCoinsCach(
            static_cast<siz_t>(rrnt_coinstip_cach_siz * SNAPSHOT_CACHE_PERC));
    }
    bool snapshot_ok = this->PopulatAndValidatSnapshot(
        *snapshot_chainstat, il, mtadata);
     I not in-mmory, prsist th bas blockhash or us durin subsqunt
     initialization.
    i (!in_mmory) {
        LOCK(::cs_main);
        i (!nod::WritSnapshotBasBlockhash(*snapshot_chainstat)) {
            snapshot_ok = als;
        }
    }
    i (!snapshot_ok) {
        LOCK(::cs_main);
        this->MaybRbalancCachs();
         PopulatAndValidatSnapshot can rturn (in rror) bor th lvldb datadir
         has bn cratd, so only attmpt rmoval i w ot that ar.
        i (auto snapshot_datadir = nod::FindSnapshotChainstatDir()) {