Add our own trivial version of stdarg.h. This makes our build

entirely self-hosted (which avoids problems when building the same
tree on multiple systems - e.g. when you have /home NFS-mounted).

Also saves around 50 bytes in total - not sure why.

src/arch/i386/include/stdarg.h

@@ -0,0 +1,22 @@
+#ifndef _STDARG_H
+#define _STDARG_H
+
+typedef void * va_list;
+
+#define va_start( ap, last ) do {	\
+		ap = ( &last + 1 );	\
+	} while ( 0 )
+
+#define va_arg( ap, type ) ({		\
+		type *_this = ap;	\
+		ap = ( _this + 1 );	\
+		*(_this);		\
+	})
+
+#define va_end( ap ) do { } while ( 0 )
+
+#define va_copy( dest, src ) do {	\
+		dest = src;		\
+	} while ( 0 )
+
+#endif /* _STDARG_H */