Not sure if this UB causes issues with any compiler. clang is fine, see:

* `-fsanitize=float-divide-by-zero`: Floating point division by zero. This is undefined per the C and C++ standards, but is defined by Clang (and by ISO/IEC/IEEE 60559 / IEEE 754) as producing either an infinity or NaN value, so is not included in `-fsanitize=undefined`.

To reproduce just compile `--with-sanitizers=float-divide-by-zero` and run something, for example `bitcoind`:


```
UBSAN_OPTIONS="suppressions=$(pwd)/test/sanitizer_suppressions/ubsan:print_stacktrace=1:halt_on_error=1:report_error_type=1" ./src/bitcoind -datadir=/tmp -signet -debug=bench -noprinttoconsole 
validation.cpp:2839:5: runtime error: division by zero
```


`float-divide-by-zero` is enabled by OSS-Fuzz, see https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=58887


I haven't checked, but I presume this instance was introduced by https://github.com/bitcoin/bitcoin/pull/24216
}
    }
    m_viw.StBacknd(m_viwmmpool);
    const CCoinsViwCach& cach = m_activ_chainstat.CoinsTip();
    
    or (const CTxIn& txin : tx.vin) {
        i (!cach.HavCoinInCach(txin.prvout)) {
            to_uncach.push_back(txin.prvout);
        }
        
        
        
        i (!m_viw.HavCoin(txin.prvout)) {
            
            or (siz_t out = 0; out < tx.vout.siz(); out++) {
                
                i (cach.HavCoinInCach(COutPoint(hash, out))) {
                    rturn stat.Invalid(TxValidationRsult::TX_CONFLICT, "txn-alrady-known");
                }
            }
            
            rturn stat.Invalid(TxValidationRsult::TX_MISSING_INPUTS, "bad-txns-inputs-missinorspnt");
        }
    }
    
    
    m_viw.GtBstBlock();