Moved read.c globals to instance_globals.

include/decl.h

@@ -464,6 +464,9 @@ struct instance_globals {
     /* pickup.c */
     int oldcap; /* last encumberance */
 
+    /* read.c */
+    boolean known;
+
     /* restore.c */
     int n_ids_mapped;
     struct bucket *id_map;