Undo XFREE change; we assume C89 compiler, but not C89 library.

src/LR0.c

@@ -157,7 +157,7 @@ free_storage (void)
   free (shiftset);
   free (kernel_base);
   free (kernel_size);
-  free (kernel_items);
+  XFREE (kernel_items);
   state_hash_free ();
 }
 

src/closure.c

@@ -241,7 +241,7 @@ closure (item_number *core, int n)
 void
 free_closure (void)
 {
-  free (itemset);
+  XFREE (itemset);
   bitset_free (ruleset);
   bitsetv_free (fderives);
 }

src/conflicts.c

@@ -545,7 +545,7 @@ conflicts_print (void)
 void
 conflicts_free (void)
 {
-  free (conflicts);
+  XFREE (conflicts);
   bitset_free (shiftset);
   bitset_free (lookaheadset);
   obstack_free (&solved_conflicts_obstack, NULL);