`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++`
LOCK(::cs_main);
    auto& view = chainstate.CoinsTip();
    
    auto add_coin = [](CCoinsViewCache& coins_view) -> COutPoint {
        Coin newcoin;
        uint256 txid = InsecureRand256();
        COutPoint outp{txid, 0};
        newcoin.nHeight = 1;
        newcoin.out.nValue = InsecureRand32();
        newcoin.out.scriptPubKey.assign((uint32_t)56, 1);
        coins_view.AddCoin(outp, std::move(newcoin), false);
        return outp;
    };
    
    
    
    
    constexpr int COIN_SIZE = is_64_bit ? 80 : 64;
    auto print_view_mem_usage = [](CCoinsViewCache& view) {
        BOOST_TEST_MESSAGE("CCoinsViewCache memory usage: " << view.DynamicMemoryUsage());
    };
    constexpr size_t MAX_COINS_CACHE_BYTES = 1024;
    
    BOOST_CHECK_EQUAL(
        chainstate.GetCoinsCacheSizeState(tx_pool, MAX_COINS_CACHE_BYTES,  0),
        CoinsCacheSizeState::OK);
    
    
    
    if (view.DynamicMemoryUsage() != 32 && view.DynamicMemoryUsage() != 16) {