test_string.rb: move and add assertions
ascii_only?
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46244 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_string.rb: move and add assertions
[Bug #9882], and more assertion for
ascii_only?
too, aspointed out by Heesob Park in [ruby-core:62846].
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46244 b2dd03c8-39d4-4d8f-98ff-823fe69b080e