Revert "rfilter initialized to UNDEFINED."

This reverts commit 716c2ceccf.

include/hack.h

@@ -22,13 +22,6 @@
         0     \
     }
 
-/* UNDEFINED and UNDEFINED_PTR are used to initialize variables whose
-   initialized value is not relied upon.  UNDEFINED can be used to
-   initialized any value type except pointers.  UNDEFINED_PTR can be used
-   only on pointer types. */
-#define UNDEFINED { 0 }
-#define UNDEFINED_PTR NULL
-
 /* symbolic names for capacity levels */
 enum encumbrance_types {
     UNENCUMBERED = 0,

src/decl.c

@@ -325,6 +325,8 @@ decl_init()
     return;
 }
 
+#define UNDEFINED { 0 }         /* move to hack.h if we are keeping */
+#define UNDEFINED_PTR NULL      /* move to hack.h if we are keeping */
 #define IVMAGIC 0xdeadbeef
 
 const struct instance_globals g_init = {

src/role.c

@@ -769,7 +769,7 @@ const struct Align aligns[] = {
 static struct {
     boolean roles[SIZE(roles)];
     short mask;
-} rfilter = UNDEFINED;
+} rfilter;
 
 STATIC_DCL int NDECL(randrole_filtered);
 STATIC_DCL char *FDECL(promptsep, (char *, int));