Test OpenStruct#methods

This supports overriding `#methods`.

Author: nevans

test/ostruct/test_ostruct.rb

@@ -195,6 +195,7 @@ def test_accessor_defines_method
     assert_respond_to(os, :foo)
     assert_equal(42, os.foo)
     assert_equal([:foo, :foo=], os.singleton_methods.sort)
+    assert_equal([:foo, :foo=], os.methods(false).sort)
   end
 
   def test_does_not_redefine