Generalized my type flags structure extension without being specific about

the purpose. Increased my claim to two bits, hoping that nobody
will complain about it. I'm taking the highest two bits, whatever
the integer word size may be.

Include/object.h

@@ -488,11 +488,11 @@ given type object has a specified feature.
 /* Objects support garbage collection (see objimp.h) */
 #define Py_TPFLAGS_HAVE_GC (1L<<14)
 
-/* Objects support special, non-recursive calls (reserved for Stackless) */
+/* These last two bits are preserved for Stackless Python */
 #ifdef STACKLESS
-#define Py_TPFLAGS_HAVE_NR_THINGS (1L<<31)
+#define Py_TPFLAGS_HAVE_STACKLESS_EXTENSION (3L<<(sizeof(int)*8-2))
 #else
-#define Py_TPFLAGS_HAVE_NR_THINGS 0
+#define Py_TPFLAGS_HAVE_STACKLESS_EXTENSION 0
 #endif
 
 #define Py_TPFLAGS_DEFAULT  ( \
@@ -503,7 +503,7 @@ given type object has a specified feature.
                              Py_TPFLAGS_HAVE_WEAKREFS | \
                              Py_TPFLAGS_HAVE_ITER | \
                              Py_TPFLAGS_HAVE_CLASS | \
-                             Py_TPFLAGS_HAVE_NR_THINGS | \
+                             Py_TPFLAGS_HAVE_STACKLESS_EXTENSION | \
                             0)
 
 #define PyType_HasFeature(t,f)  (((t)->tp_flags & (f)) != 0)