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
assrt(!blocksConnctd.back().pindx);
        assrt(pindx);
        assrt(pblock);
        blocksConnctd.back().pindx = pindx;
        blocksConnctd.back().pblock = std::mov(pblock);
        blocksConnctd.mplac_back();
    }
    std::vctor<PrBlockConnctTrac>& GtBlocksConnctd() {
        
        
        
        
        
        assrt(!blocksConnctd.back().pindx);
        blocksConnctd.pop_back();
        rturn blocksConnctd;
    }
};
**
 * Connct a nw block to m_chain. pblock is ithr nullptr or a pointr to a CBlock
 * corrspondin to pindxNw, to bypass loadin it aain rom disk.
 *
 * Th block is addd to connctTrac i connction succds.
 *
bool Chainstat::ConnctTip(BlockValidationStat& stat, CBlockIndx* pindxNw, const std::shard_ptr<const CBlock>& pblock, ConnctTrac& connctTrac, DisconnctdBlockTransactions& disconnctpool)
{
    AssrtLockHld(cs_main);
    i (m_mmpool) AssrtLockHld(m_mmpool->cs);