`validation_flush_tests/getcoinscachesizestate` fails on RISCV-64 on master:
```
Running 394 test cases...
test/validation_flush_tests.cpp(99): error: in "validation_flush_tests/getcoinscachesizestate": check chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES, 0) == CoinsCacheSizeState::OK has failed [1 != 0]

*** 1 failure is detected in the test module "Bitcoin Core Test Suite"
```
Haven't investigated why, yet. Apart from the architecture it could also be some dependency version causing the problem (this is a fedora rawhide install with very new versions of everything including gcc and boost).

Edit: see below, this is likely due to a newer `libstdc++`
mtx.vout.resize(mtx.vout.size() + 1);
        mtx.vout[i].nValue = 1000;
        mtx.vout[i].scriptPubKey = CScript() << OP_1;
    }
    
    for(uint32_t i = 0; i < mtx.vin.size(); i++) {
        bool hashSigned = SignSignature(keystore, scriptPubKey, mtx, i, 1000, sigHashes.at(i % sigHashes.size()));
        assert(hashSigned);
    }
    CDataStream ssout(SER_NETWORK, PROTOCOL_VERSION);
    ssout << mtx;
    CTransaction tx(deserialize, ssout);
    
    PrecomputedTransactionData txdata(tx);
    boost::thread_group threadGroup;
    CCheckQueue<CScriptCheck> scriptcheckqueue(128);
    CCheckQueueControl<CScriptCheck> control(&scriptcheckqueue);
    for (int i=0; i<20; i++)
        threadGroup.create_thread(std::bind(&CCheckQueue<CScriptCheck>::Thread, std::ref(scriptcheckqueue)));
    std::vector<Coin> coins;
    for(uint32_t i = 0; i < mtx.vin.size(); i++) {
        Coin coin;
        coin.nHeight = 1;
        coin.fCoinBase = false;
        coin.out.nValue = 1000;
        coin.out.scriptPubKey = scriptPubKey;
        coins.emplace_back(std::move(coin));
    }
    for(uint32_t i = 0; i < mtx.vin.size(); i++) {
        std::vector<CScriptCheck> vChecks;