fix reported crash of TTY_PERM_INVENT segfaulting

Options processing can be early, even before ttyDisplay is allocated.
If we find that TTY_PERM_INVENT initialization is happening too early,
just set a marker (iflags.perm_invent_pending) to try again a bit later.

The changes in win/share are just to be able to sucessfully
reproduce the original issue on Windows. It was easily reproduced
on Unix, just by building with TTY_PERM_INVENT in include/config.h
and setting OPTIONS=perm_invent in config file.

include/flag.h

@@ -319,6 +319,7 @@ struct instance_flags {
     boolean news;             /* print news */
     boolean num_pad;          /* use numbers for movement commands */
     boolean perm_invent;      /* display persistent inventory window */
+    boolean perm_invent_pending;  /* need to try again */
     boolean renameallowed;    /* can change hero name during role selection */
     boolean renameinprogress; /* we are changing hero name */
     boolean sounds;           /* master on/off switch for using soundlib */