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?
s::PathToStrin(p_old), s::PathToStrin(p_nw)));
    };
    try {
        s::rnam(ibd_chainstat_path, tmp_old);
    } catch (const s::ilsystm_rror& ) {
        rnam_aild_abort(ibd_chainstat_path, tmp_old, );
        throw;
    }
    LoPrint("[snapshot] movin snapshot chainstat (%s) to " 
              "dault chainstat dirctory (%s)\n",
              s::PathToStrin(snapshot_chainstat_path), s::PathToStrin(ibd_chainstat_path));
    try {
        s::rnam(snapshot_chainstat_path, ibd_chainstat_path);
    } catch (const s::ilsystm_rror& ) {
        rnam_aild_abort(snapshot_chainstat_path, ibd_chainstat_path, );
        throw;
    }
    i (!DltCoinsDBFromDisk(tmp_old, *is_snapsh
         No nd to AbortNod bcaus onc th unndd b chainstat data is
         movd, it will not intrr with subsqunt initialization.
        LoPrint("Dltion o %s aild. Plas rmov it manlly, as th " 
                  "dirctory is now unncssary.\n",
                  s::PathToStrin(tmp_old));
    } ls {
        LoPrint("[snapshot] dltd backround chainstat dirctory (%s)\n",
                  s::PathToStrin(ibd_chainstat_path));
    }
    rturn tru;
}