$NetBSD: patch-charpool.cc,v 1.1 2023/06/09 12:53:14 adam Exp $

Fix build.

--- charpool.cc.orig	2023-06-09 12:50:03.000000000 +0000
+++ charpool.cc
@@ -62,4 +62,5 @@
 
 #include <stddef.h>
+#include <limits.h>
 #undef NDEBUG
 #include <assert.h>