`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++`
BOOST_ERROR("Bad test: " << strTest);
                continue;
            }
            std::map<COutPoint, CScript> mapprevOutScriptPubKeys;
            std::map<COutPoint, int64_t> mapprevOutValues;
            UniValue inputs = test[0].get_array();
            bool fValid = true;
	    for (unsigned int inpIdx = 0; inpIdx < inputs.size(); inpIdx++) {
	        const UniValue& input = inputs[inpIdx];
                if (!input.isArray())
                {
                    fValid = false;
                    break;
                }
                UniValue vinput = input.get_array();
                if (vinput.size() < 3 || vinput.size() > 4)
                {
                    fValid = false;
                    break;
                }
                COutPoint outpoint(uint256S(vinput[0].get_str()), vinput[1].get_int());
                mapprevOutScriptPubKeys[outpoint] = ParseScript(vinput[2].get_str());
                if (vinput.size() >= 4)
                {
                    mapprevOutValues[outpoint] = vinput[3].get_int64();
                }
            }
            if (!fValid)
            {
                BOOST_ERROR("Bad test: " << strTest);