remove unused auxuality data field proc->aux

src/codegen.c

@@ -670,7 +670,7 @@ pic_defun(pic_state *pic, const char *name, pic_func_t cfunc)
   struct pic_proc *proc;
   int idx;
 
-  proc = pic_proc_new_cfunc(pic, cfunc, pic_undef_value());
+  proc = pic_proc_new_cfunc(pic, cfunc);
   idx = scope_global_define(pic, name);
   pic->globals[idx] = pic_obj_value(proc);
 }

src/gc.c

@@ -170,7 +170,6 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
     if (proc->env) {
       gc_mark_object(pic, (struct pic_object *)proc->env);
     }
-    gc_mark(pic, proc->aux);
     break;
   }
   case PIC_TT_PORT: {

src/proc.c

@@ -11,12 +11,11 @@ pic_proc_new(pic_state *pic, struct pic_irep *irep, struct pic_env *env)
   proc->cfunc_p = false;
   proc->u.irep = irep;
   proc->env = env;
-  proc->aux = pic_undef_value();
   return proc;
 }
 
 struct pic_proc *
-pic_proc_new_cfunc(pic_state *pic, pic_func_t cfunc, pic_value aux)
+pic_proc_new_cfunc(pic_state *pic, pic_func_t cfunc)
 {
   struct pic_proc *proc;
 
@@ -24,7 +23,6 @@ pic_proc_new_cfunc(pic_state *pic, pic_func_t cfunc, pic_value aux)
   proc->cfunc_p = true;
   proc->u.cfunc = cfunc;
   proc->env = NULL;
-  proc->aux = aux;
   return proc;
 }