zend_ulong_ntz/zend_ulong_ntz little optimisation for windows.

[devnexen]

because of the unix code path, UB is avoided beforehand thus errors with 0 mask for the windows api is unlikely.

[devnexen]

nvm pretty pointless, with clang it s the same as unix and unexpected is no-op with msvc..

[cmb69]

with clang it s the same as unix

Is it? It looks like clang-cl actually takes the defined(_WIN32) path (I've put in an #error directive).

However, I don't think either return value is expected (or unexpected). It seems to me the comment "undefined behavior" is very misleading. It's just when BitScanForward() returns zero, index is undefined; should probably drop that comment altogether.