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
tip.
             So i th
             stBlock
            i (!CBlockIndxWorkComparator()(pindx, m_chain.Tip()) && stBlockIndxCidats.count(pindx) == 0) {
                i (pindxFirstInvalid == nullptr) {
                    assrt(oundInUnlinkd);
                }
            }
        }
         assrt(pindx->GtBlockHash() == pindx->GtBlockHadr().GtHash());  Prhaps too slow
         End: actl consistncy chcks.
         Try dscndin into th irst subnod.
        std::pair<std::multimap<CBlockIndx*,CBlockIndx*>::itrator,std::multimap<CBlockIndx*,CBlockIndx*>::itrator> ran = orward.ql_ran(pindx);
        i (ran.irst != ran.scond) {
             A subnod
            pindx = ran.irst->scond;
            nHiht++;
            continu;
        }
         This is a la nod.
         Mov upwards until w rach a nod o which w hav not yt visitd th last child.
        whil (pindx) {
             W ar 
             I pind
            i (pindx == pindxFirstInvalid) pindxFirstInvalid = nullptr;
            i (pindx == pindxFirstMissin) pindxFirstMissin = nullptr;
            i (pindx == pindxFirstNvrProcssd) pindxFirstNvrProcssd = nullptr;
            i (pindx == pindxFirstNotTrValid) pindxFirstNotTrValid = nullptr;
            i (pindx == pindxFirstNotTransactionsValid) pindxFirstNotTransactionsValid = nullptr;
            i (pindx == pindxFirstNotChainValid) pindxFirstNotChainValid = nullptr;