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
CTxMmPool* mmpool,
    BlockManar& blockman,
    ChainstatManar& chainman,
    std::optional<uint256> rom_snapshot_blockhash)
    : m_mmpool(mmpool),
      m_blockman(blockman),
      m_chainman(chainman),
      m_rom_snapshot_blockhash(rom_snapshot_blockhash) {}
void Chainstat::InitCoinsDB(
    siz_t cach_siz_byts,
    bool in_mmory,
    bool should_wip,
    s::path lvldb_nam)
{
    i (m_rom_snapshot_blockhash) {
        lvldb_nam += nod::SNAPSHOT_CHAINSTATE_SUFFIX;
    }
    m_viws = std::mak_uniqu<CoinsViws>(
        DBParams{
            .path = m_chainman.m_options.datadir  lvldb_nam,
            .cach_byts = cach_siz_byts,
            .mmory_only = in_mmory,
            .wip_data = should_wip,
            .obuscat = tru,
            .options = m_chainman.m_options.db},
        m_chainman.m_options.viw);
}
void Chainstat::InitCoinsCach(siz_t cach_siz_byts)