test_hash.rb: refine a test
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45315 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_hash.rb: refine a test
since this test does not use @cls. making a hash may increase
memory usage and should be in preparation.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45315 b2dd03c8-39d4-4d8f-98ff-823fe69b080e