9911229650
Enable varargs support for calling conventions other than C or cdecl This patch makes it possible to use varargs for calling conventions, which are either based on C (efiapi) or C is based on them (sysv64 and win64). Also pinging ``@phlopsi,`` because he noticed first this oversight when writing a library for UEFI.
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.