anchor.diff:  static int gen_error;
   struct type **gen_tphead(), **gen_tpmiddle();
   struct sdef *gen_align_to_next();
  +struct e_stack *p_stack;
   }
   
   /*	initial_value recursively guides the initialisation expression.
  
positive.code: 	struct type **tpp;
  {
  	register struct type *tp = *tpp;
  	register struct e_stack *p = new_e_stack();
  	register struct sdef *sd;
  
  	if (gen_error) return tpp;
  	p->next = p_stack;
  	p_stack = p;
  	p->s_nested = nest;
  
negative.code: 	}
  }
  
  struct type **
  arr_elem(tpp, p)
  	struct type **tpp;
  