clang-cl x64 build isn't including masm-x64.asm

[lukester1975]

Hello

I have a "fix" here lukester1975@d4f8934 but as someone who avoid cmake like the plague, I wouldn't like to say it's perfect. Works for me for x64 cl or clang-cl vs2022/26 but maybe there's a more canonical way to do that test.

Thanks!