Fix bytes hash with Swift 3.0.x
Fix bytes hash with Swift 3.0.x

Apparently, Data.hashValue was broken at one time.

thomasvl/swift-protobuf,apple/swift-protobuf,tbkka/swift-protobuf,allevato/swift-protobuf,cburrows/swift-protobuf,cburrows/swift-protobuf,tbkka/swift-protobuf,apple/swift-protobuf,allevato/swift-protobuf,apple/swift-protobuf,cburrows/swift-protobuf,cburrows/swift-protobuf,tbkka/swift-protobuf,thomasvl/swift-protobuf,tbkka/swift-protobuf,thomasvl/swift-protobuf,allevato/swift-protobuf,thomasvl/swift-protobuf,thomasvl/swift-protobuf,tbkka/swift-protobuf,apple/swift-protobuf,apple/swift-protobuf,allevato/swift-protobuf,allevato/swift-protobuf,apple/swift-protobuf,tbkka/swift-protobuf,cburrows/swift-protobuf,allevato/swift-protobuf,cburrows/swift-protobuf,tbkka/swift-protobuf,cburrows/swift-protobuf,thomasvl/swift-protobuf,thomasvl/swift-protobuf,apple/swift-protobuf,allevato/swift-protobuf