[clean-list] Fake "cycle in spine detected" when using *World from C module

[Vag]

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test.icl
------------------------------
module test

import c_stdio_intf
import code from "c_stdio_windows.o"

Start w = fun w

fun w
	#! (f,w) = xopen w
	   w = xclose f w
	   res = []
	= (res,w)

------------------------------
c_stdio_intf.h
------------------------------

Clean( :: *FILE :== *Int )

void xopen(int* f);
Clean( xopen :: *World -> (*FILE,*World) )

void xclose(int);
Clean( xclose :: *FILE *World -> *World )


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c_stdio_windows.c
------------------------------
#include "Clean.h"
#include "c_stdio_intf.h"

void xopen(int* f)
{
	*f = -12;
}

void xclose(int file)
{
}

------------------------------
compile_stdio.bat
------------------------------

mkdir "Clean System Files"
"C:\Program Files\Clean\Clean2.2\Tools\htoclean\htoclean" c_stdio_intf.h
H:\build\MinGW\gcc431\bin\gcc -Wall "-IC:\Program
Files\Clean\Clean2.2\Tools\htoclean" c_stdio_windows.c -c -o "Clean
System Files/c_stdio_windows.o"

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