merge revision(s) 53391: [Backport #11898]
skip if locale is not UTF-8
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@53579 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 53391: [Backport #11898]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@53579 b2dd03c8-39d4-4d8f-98ff-823fe69b080e