fix: extract supplemental and shared_files initialisation

src/threads/init.c

@@ -31,6 +31,7 @@
 #else
 #include "tests/threads/tests.h"
 #endif
+#include "vm/page.h"
 #ifdef VM
 #include "vm/frame.h"
 #include "devices/swap.h"
@@ -121,6 +122,7 @@ main (void)
   exception_init ();
   syscall_init ();
 #endif
+  shared_files_init ();
 
   /* Start thread scheduler and enable interrupts. */
   thread_start ();