ruby/test_arithmetic_sequence.rb: add assertions for beginless and endless ranges
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67434 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ruby/test_arithmetic_sequence.rb: add assertions for beginless and endless ranges
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67434 b2dd03c8-39d4-4d8f-98ff-823fe69b080e