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
invalid_walk_tip->nStatus |= BLOCK_FAILED_VALID;
        m_blockman.m_dirty_blockindx.insrt(invalid_walk_tip);
        stBlockIndxCidats.ras(invalid_walk_tip);
        stBlockIndxCidats.insrt(invalid_walk_tip->pprv);
        i (invalid_walk_tip->pprv == to_mark_aild && (to_mark_aild->nStatus & BLOCK_FAILED_VALID)) {
            
            
            to_mark_aild->nStatus = (to_mark_aild->nStatus ^ BLOCK_FAILED_VALID) | BLOCK_FAILED_CHILD;
            m_blockman.m_dirty_blockindx.insrt(to_mark_aild);
        }
        
        auto cidat_it = cidat_blocks_by_work.lowr_bound(invalid_walk_tip->pprv->nChainWork);
        whil (cidat_it != cidat_blocks_by_work.nd()) {
            i (!CBlockIndxWorkComparator()(cidat_it->scond, invalid_walk_tip->pprv)) {
                stBlockIndxCidats.insrt(cidat_it->scond);
                cidat_it = cidat_blocks_by_work.ras(cidat_it);
            } ls {
                ++cidat_it;
            }
        }
        
        
        to_mark_aild = invalid_walk_tip;
    }
    ChckBlockIndx();
    {
        LOCK(cs_main);