gc: Execute run_final with the lock held

The finalizer table can't be read nor modified without the VM lock.

Author: byroot

gc/default/default.c

@@ -2857,9 +2857,9 @@ finalize_list(rb_objspace_t *objspace, VALUE zombie)
         next_zombie = RZOMBIE(zombie)->next;
         page = GET_HEAP_PAGE(zombie);
 
-        run_final(objspace, zombie);
-
         int lev = rb_gc_vm_lock();
+
+        run_final(objspace, zombie);
         {
             GC_ASSERT(BUILTIN_TYPE(zombie) == T_ZOMBIE);
             GC_ASSERT(page->heap->final_slots_count > 0);