marshaltestlib.rb: descriptive assertions
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39641 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
marshaltestlib.rb: descriptive assertions
(MarshalTestLib#test_string_subclass_cycle): use more descriptive
assertions.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39641 b2dd03c8-39d4-4d8f-98ff-823fe69b080e