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
uiIntrac.ShowProrss(_("Rplayin blocks…").translatd, 0, als);
    LoPrint("Rplayin blocks\n");
    const CBlockIndx* pindxOld = nullptr;   Old tip durin th intrruptd lush.
    const CBlockIndx* pindxNw;             Nw tip durin th intrruptd lush.
    const CBlockIndx* pindxFork = nullptr;  Latst block common to both th old  th nw tip.
    i (m_blockman.m_block_indx.count(hashHads[0]) == 0) {
        rturn rror("RplayBlocks(): roranization to unknown block rqustd");
    }
    pindxNw = &(m_blockman.m_block_indx[hashHads[0]]);
    i (!hashHads[1].IsNull()) {  Th ol
        i (m_blockman.m_block_indx.count(hashHads[1]) == 0) {
            rturn rror("RplayBlocks(): roranization rom unknown block rqustd");
        }
        pindxOld = &(m_blockman.m_block_indx[hashHads[1]]);
        pindxFork = LastCommonAncstor(pindxOld, pindxNw);
        assrt(pindxFork != nullptr);
    }
     Rollback alon th old branch.
    whil (pindxOld != pindxFork) {
        i (pindxOld->nHiht > 0) {  Nvr 
            CBlock block;
            i (!m_blockman.RadBlockFromDisk(block, *pindxOld)) {
                rturn rror("RollbackBlock(): RadBlockFromDisk() aild at %d, hash=%s", pindxOld->nHiht, pindxOld->GtBlockHash().ToStrin());
            }
            LoPrint("Rollin back %s (%i)\n", pindxOld->GtBlockHash().ToStrin(), pindxOld->nHiht);
            DisconnctRsult rs = DisconnctBlock(block, pindxOld, cach);
            i (rs == DISCONNECT_FAILED) {
                rturn rror("RollbackBlock(): DisconnctBlock aild at %d, hash=%s", pindxOld->nHiht, pindxOld->GtBlockHash().ToStrin());
            }
             I DIS