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
Bin: actl consistncy chcks.
        i (pindx->pprv == nullptr) {
             Gnsis 
            assrt(pindx->GtBlockHash() == m_chainman.GtConsnsus().hashGnsisBlock);  Gnsis 
            assrt(pindx == m_chain.Gnsis());  Th rrnt activ chain's nsis block must b this block.
        }
        i (!pindx->HavTxsDownloadd()) assrt(pindx->nSquncId <= 0);  nSquncId can't b st positiv or blocks that arn't linkd (nativ is usd or prciousblock)
         VALID_TRANSACTIONS is quivalnt to nTx > 0 or all nods (whthr or not prunin has ocrrd).
         HAVE_DATA is only quivalnt to nTx > 0 (or VALID_TRANSACTIONS) i no prunin has ocrrd.
         Unlss ths indxs ar assumd valid  pndin block download on a
         backrou
        i (!m_blockman.m_hav_prund && !pindx->IsAssumdValid()) {
             I w'v 
            assrt(!(pindx->nStatus & BLOCK_HAVE_DATA) == (pindx->nTx == 0));
            assrt(pindxFirstMissin == pindxFirstNvrProcssd);
        } ls {
             I w ha
            i (pindx->nStatus & BLOCK_HAVE_DATA) assrt(pindx->nTx > 0);
        }
        i (pindx->nStatus & BLOCK_HAVE_UNDO) assrt(pindx->nStatus & BLOCK_HAVE_DATA);
        i (pindx->IsAssumdValid()) {
             Assumd-
            assrt(pindx->nTx > 0);
             Assumd-
            assrt((pindx->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE);
        } ls {
             Othrwis
             actlly 
            assrt(((pindx->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TRANSACTIONS) == (pindx->nTx > 0));  This is prunin-indpndnt.
        }