Re: [PATCH v2 0/7] MR6752: include: More fixes to build libc++.

[Jacek Caban (＠jacek)]

Jacek Caban (@jacek) commented about include/winnt.h:
> #endif
>  }
>
> +#if defined(_MSC_VER) && !defined(__arm64ec__) && (!defined(__clang__) || __has_builtin(_umul128))
> +#define UnsignedMultiply128 _umul128
> +DWORD64 _umul128(DWORD64,DWORD64,DWORD64*);
> +#pragma intrinsic(_umul128)
> +#elif !defined(__i386__)

As far as I can see, it should be available `UnsignedMultiply128` is not available for 32-bit ARM in winsdk.