Test finalizer is ran in bootstraptest

bootstraptest/test_finalizer.rb

@@ -6,3 +6,11 @@ ObjectSpace.define_finalizer(b1,proc{b1.inspect})
 ObjectSpace.define_finalizer(a2,proc{a1.inspect})
 ObjectSpace.define_finalizer(a1,proc{})
 }, '[ruby-dev:35778]'
+
+assert_equal 'true', %q{
+  obj = Object.new
+  id = obj.object_id
+
+  ObjectSpace.define_finalizer(obj, proc { |i| print(id == i) })
+  nil
+}