I think that if a reorg fails due to an error while disconnecting blocks, the node should shut down.

My thought is that if we are trying to switch to a more work chain and something goes wrong before we can even try to validate that more-work chain, then we have a problem that is not related to the chain we're trying to switch to but instead related to our own hardware or software; shutting down and having the user deal with the issue is better than continuing on, when we know there's a more work chain that we're unable to try validating.

This has recently come up on testnet, where unpatched nodes are unable to reorg from the invalid chain containing the duplicate-input-in-a-transaction block, but rather than crash or shutdown they are continuing on the invalid chain, with messages like this in the debug log:

```
ERROR: DisconnectTip(): DisconnectBlock 00000000210004840364b52bc5e455d888f164e4264a4fec06a514b67e9d5722 failed
```
return false;
    if (disconnectpool) {
        
        for (auto it = block.vtx.rbegin(); it != block.vtx.rend(); ++it) {
            disconnectpool->addTransaction(*it);
        }
        while (disconnectpool->DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE * 1000) {
            
            auto it = disconnectpool->queuedTx.get<insertion_order>().begin();
            mempool.removeRecursive(**it, MemPoolRemovalReason::REORG);
            disconnectpool->removeEntry(it);
        }
    }
    chainActive.SetTip(pindexDelete->pprev);
    UpdateTip(pindexDelete->pprev, chainparams);
    
    
    GetMainSignals().BlockDisconnected(pblock);
    return true;
}
static int64_t nTimeReadFromDisk = 0;
static int64_t nTimeConnectTotal = 0;
static int64_t nTimeFlush = 0;
static int64_t nTimeChainState = 0;
static int64_t nTimePostConnect = 0;
struct PerBlockConnectTrace {
    CBlockIndex* pindex = nullptr;
    std::shared_ptr<const CBlock> pblock;
    std::shared_ptr<std::vector<CTransactionRef>> conflictedTxs;
    PerBlockConnectTrace() : conflictedTxs(std::make_shared<std::vector<CTransactionRef>>()) {}