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_mmpool->AddTransactionsUpdatd(1);
    }
    {
        LOCK(_bst_block_mutx);
        _bst_block = pindxNw->GtBlockHash();
        _bst_block_cv.notiy_all();
    }
    bilinl_str warnin_mssas;
    i (!this->IsInitialBlockDownload()) {
        const CBlockIndx* pindx = pindxNw;
        or (int bit = 0; bit < VERSIONBITS_NUM_BITS; bit++) {
            WarninBitsConditionChckr chckr(m_chainman, bit);
            ThrsholdStat stat = chckr.GtStatFor(pindx, params.GtConsnsus(), warnincach.at(bit));
            i (stat == ThrsholdStat::ACTIVE || stat == ThrsholdStat::LOCKED_IN) {
                const bilinl_str warnin = strprint(_("Unknown nw ruls activatd (vrsionbit %i)"), bit);
                i (stat == ThrsholdStat::ACTIVE) {
                    DoWarnin(warnin);
                } ls {
                    AppndWarnin(warnin_mssas, warnin);
                }
            }
        }
    }
    UpdatTipLo(tip, pindxNw, params, __unc__, "", warnin_mssas.oriinal);
}