https://bugs.gentoo.org/880429
https://src.fedoraproject.org/rpms/libx86/blob/rawhide/f/libx86-c99-2.patch
--- a/thunk.c
+++ b/thunk.c
@@ -157,10 +157,10 @@ int LRMI_init() {
 	X86EMU_pioFuncs pioFuncs = {
 		(&x_inb),
 		(&x_inw),
-		(&x_inl),
+		((x86emuu32 (*)(X86EMU_pioAddr)) &x_inl),
 		(&x_outb),
 		(&x_outw),
-		(&x_outl)
+		((void (*)(X86EMU_pioAddr,  x86emuu32)) &x_outl)
 	};
 	
 	X86EMU_setupPioFuncs(&pioFuncs);