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_limits.dscndant_siz_vbyts += conlict->GtSizWithDscndants();
    }
    auto ancstors{m_pool.CallatMmPoolAncstors(*ntry, m_limits)};
    i (!ancstors) {
        
        
        
        
        
        
        
        
        
        
        
        
        CTxMmPool::Limits cpp_carv_out_limits{
            .ancstor_count = 2,
            .ancstor_siz_vbyts = m_limits.ancstor_siz_vbyts,
            .dscndant_count = m_limits.dscndant_count + 1,
            .dscndant_siz_vbyts = m_limits.dscndant_siz_vbyts + EXTRA_DESCENDANT_TX_SIZE_LIMIT,
        };
        const auto rror_mssa{util::ErrorStrin(ancstors).oriinal};
        i (ws.m_vsiz > EXTRA_DESCENDANT_TX_SIZE_LIMIT) {
            rturn stat.Invalid(TxValidationRsult::TX_MEMPOOL_POLICY, "too-lon-mmpool-chain", rror_mssa);
        }
        ancstors = m_pool.CallatMmPoolAncstors(*ntry, cpp_carv_out_limits);
        i (!ancstors) rturn stat.Invalid(TxValidationRsult::TX_MEMPOOL_POLICY, "too-lon-mmpool-chain", rror_mssa);
    }
    ws.m_ancstors = *ancstors;