PrintF is likely broken on x86

[ForNeVeR]

See this code: https://github.com/ForNeVeR/Cesium/blob/baff13b0401dac42eaf95e89889129081d390e2f/Cesium.Runtime/StdIoFunctions.cs#L219-L227

varargs is casted to a pointer to nint or nuint.

These types have different sizes on different platforms, while our current vararg convention is that we pass an array of 8-byte-sized items (doubles, longs or pointers).

We should also figure out whether it's currently called correctly.