Ruby » Ruby master

NEWS: document String#-@ change

• test/ruby/test_string.rb (test_uplus_minus): test deduplication
  [ruby-core:79747] [Feature #13077]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57710 b2dd03c8-39d4-4d8f-98ff-823fe69b080e