Moved read.c globals to instance_globals.

src/decl.c

@@ -348,6 +348,9 @@ const struct instance_globals g_init = {
     /* pickup.c */
     0,  /* oldcap */
 
+    /* read.c */
+    UNDEFINED_VALUE, /* known */
+
     /* restore.c */
     0, /* n_ids_mapped */
     0, /* id_map */