Work around auto-dereference crash in rustboot.

src/Makefile

@@ -347,7 +347,6 @@ MUT_BOX_XFAILS := $(addprefix test/run-pass/, \
 TEST_XFAILS_X86 :=  $(MUT_BOX_XFAILS) \
                     test/run-pass/mlist-cycle.rs \
                     test/run-pass/clone-with-exterior.rs \
-                    test/run-pass/destructor-ordering.rs \
                     test/run-pass/obj-as.rs \
                     test/run-pass/vec-slice.rs \
                     test/run-pass/fn-lval.rs \

src/test/run-pass/destructor-ordering.rs

@@ -18,7 +18,7 @@ state obj order_tracker(mutable int init) {
 
 obj dorder(@order_tracker tracker, int order, str message) {
   drop {
-    tracker.assert_order(order, message);
+    (*tracker).assert_order(order, message);
   }
 }