`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++`
reason.clear();
    BOOST_CHECK(!IsStandardTx(CTransaction(t), reason));
    BOOST_CHECK_EQUAL(reason, "version");
    t.nVersion = 0;
    reason.clear();
    BOOST_CHECK(!IsStandardTx(CTransaction(t), reason));
    BOOST_CHECK_EQUAL(reason, "version");
    t.nVersion = 3;
    reason.clear();
    BOOST_CHECK(!IsStandardTx(CTransaction(t), reason));
    BOOST_CHECK_EQUAL(reason, "version");
    
    t.nVersion = 1;
    BOOST_CHECK(IsStandardTx(CTransaction(t), reason));
    t.nVersion = 2;
    BOOST_CHECK(IsStandardTx(CTransaction(t), reason));
    
    
    dustRelayFee = CFeeRate(3702);
    
    t.vout[0].nValue = 673 - 1;
    reason.clear();
    BOOST_CHECK(!IsStandardTx(CTransaction(t), reason));
    BOOST_CHECK_EQUAL(reason, "dust");
    
    t.vout[0].nValue = 673;
    BOOST_CHECK(IsStandardTx(CTransaction(t), reason));
    dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE);
    t.vout[0].scriptPubKey = CScript() << OP_1;
    reason.clear();