fix compilation with the Windows SDK
Compilation with the Windows SDK is achieved with clang-cl in Visual Studio 22, generated by meson.
This is a cleaner environment than mingw-w64 to pick what is regular Windows API and portable code.
clang-cl is a Clang version distributed by MS that understands cl.exe commands and the MS code syntax. It defines _MSC_VER
and __clang__
.