Add Ref/Box and ThreadSpecific examples
Add Ref/Box and ThreadSpecific examples

Nirma/swift-evolution,natecook1000/swift-evolution,abertelrud/swift-evolution,ddunbar/swift-evolution,DevAndArtist/swift-evolution,anandabits/swift-evolution,ddunbar/swift-evolution,apple/swift-evolution,anandabits/swift-evolution,natecook1000/swift-evolution,Nirma/swift-evolution,hartbit/swift-evolution,apple/swift-evolution,hartbit/swift-evolution,abertelrud/swift-evolution,DevAndArtist/swift-evolution