Impliment Microsoft variadic ABI

[ZacWalk]

Windows used the aarch64 abi for everything except variadic functions. The assumption is that this will be an issue when calling variadic Methods in the Microsoft CRT like printf. However, in most cases looks like the mingw implementation of printf is used.

I have marked this as an enhancement because I am not sure if is essential for our initial upstream. The Micorosft aarch64 ABI follows AArch64 EABI for everything except variadic functions. We need to investigate what problems there are in real-world scenarios caused by this.

Relevant documentation:

• https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170#addendum-variadic-functions