use int instead of signed char for comparing loadsym, as absolute paths can exceed 128 characters

pd/src/m_class.c

@@ -251,8 +251,8 @@ t_class *class_new(t_symbol *s, t_newmethod newmethod, t_method freemethod,
                 /* if we're loading an extern it might have been invoked by a
                 longer file name; in this case, make this an admissible name
                 too. */
-            char *loadstring = class_loadsym->s_name,
-                l1 = strlen(s->s_name), l2 = strlen(loadstring);
+            char *loadstring = class_loadsym->s_name;
+            int l1 = strlen(s->s_name), l2 = strlen(loadstring);
             if (l2 > l1 && !strcmp(s->s_name, loadstring + (l2 - l1)))
                 class_addmethod(pd_objectmaker, (t_method)newmethod,
                     class_loadsym,