title: Fail to decode Int with NSCoder in Swift
body: <p>I am using Xcode8 Beta with Swift 3.0. I tried to encode a simple object base on NSObject, but I cannot decode Int or NSInteger type. (The encoding process is OK)</p>
  
  <p><a href="https://i.stack.imgur.com/GN6Yi.png" rel="noreferrer"><img src="https://i.stack.imgur.com/GN6Yi.png" alt="enter image description here"></a></p>
  
  <p>codes</p>
  
  <pre><code>class Model : NSObject, NSCoding {
      var seq: NSNumber?
      var seq2: Int? // problem with seq2, NSInteger is not ok, either
      var id: String?
      var value: String?
  
      override init() {
          super.init()
      }
  
      required init?(coder aDecoder: NSCoder){
          self.seq = aDecoder.decodeObject(forKey: "seq") as? NSNumber
          self.seq2 = aDecoder.decodeInteger(forKey: "seq2")
          self.id = aDecoder.decodeObject(forKey: "id") as? String
          self.value = aDecoder.decodeObject(forKey: "value") as? String
      }
  
      func encode(with aCoder: NSCoder){
          aCoder.encode(seq, forKey: "seq")
          aCoder.encode(seq2, forKey: "seq2")
          aCoder.encode(id, forKey: "id")
          aCoder.encode(value, forKey: "value")
      }
  }
  </code></pre>