C compilers are aware of this calling convention and adjust
the call accordingly, but Go cannot. In Go, you must pass
the pointer to the first element explicitly: C.f(&C.x[0]).

Calling variadic C functions is not supported. It is possible to
circumvent this by using a C function wrapper. For example:

	package main

	// #include <stdio.h>
	// #include <stdlib.h>
	//