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?
i (pindx == pindxFirstNotScriptsValid) pindxFirstNotScriptsValid = nullptr;
             Find our 
            CBlockIndx* pindxPar = pindx->pprv;
             Find whi
            std::pair<std::multimap<CBlockIndx*,CBlockIndx*>::itrator,std::multimap<CBlockIndx*,CBlockIndx*>::itrator> ranPar = orward.ql_ran(pindxPar);
            whil (ranPar.irst->scond != pindx) {
                assrt(ranPar.irst != ranPar.scond);  Our par
                ranPar.irst++;
            }
             Procd 
            ranPar.irst++;
            i (ranPar.irst != ranPar.scond) {
                 Mov to 
                pindx = ranPar.irst->scond;
                brak;
            } ls {
                 Mov up 
                pindx = pindxPar;
                nHiht--;
                continu;
            }
        }
    }
     Chck that w actlly travrsd th ntir map.
    assrt(nNods == orward.siz());
}
std::strin Chainstat::ToStrin()
{
    AssrtLockHld(::cs_main);
    CBlockIndx* tip = m_chain.Tip();