This removes the related tests, and puts the related specs behind
version guards. This affects all code in lib, including some
libraries that may want to support older versions of Ruby.
* Other ruby implementations use the spec/ruby directory.
[Misc #13792] [ruby-core:82287]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59979 b2dd03c8-39d4-4d8f-98ff-823fe69b080e