word hashcodes: Don't unsafely set the hashcode for a word to be a bignum. Revert foldable, type declaration for word hashcode*.

basis/disjoint-sets/disjoint-sets-tests.factor

@@ -2,7 +2,6 @@ USING: tools.test disjoint-sets namespaces slots.private ;
 IN: disjoint-sets.tests
 
 SYMBOL: +blah+
--405534154 +blah+ 1 set-slot
 
 SYMBOL: uf
 

core/words/words.factor

@@ -262,8 +262,9 @@ M: word forget*
         tri
     ] if ;
 
+! Can be foldable because the hashcode itself is immutable
 M: word hashcode*
-    nip 1 slot { integer } declare ; inline
+    nip 1 slot { fixnum } declare ; inline foldable
 
 M: word literalize <wrapper> ;