add picrin/proc.h

src/gc.c

@@ -3,6 +3,7 @@
 #include "picrin.h"
 #include "picrin/gc.h"
 #include "picrin/irep.h"
+#include "picrin/proc.h"
 
 #if GC_DEBUG
 # include <stdio.h>

src/write.c

@@ -2,6 +2,7 @@
 #include <stdlib.h>
 
 #include "picrin.h"
+#include "picrin/proc.h"
 
 void
 pic_debug(pic_state *pic, pic_value obj)