message: Add a test for an OptionSet with a computed rawValue property.
diff: @@ -15,12 +15,26 @@ struct Options : OptionSet {
  let rawValue: Int
  }
  +struct ComputedOptions : OptionSet {
  + init(rawValue: Int) { storedValue = rawValue }
  + let storedValue: Int
  + var rawValue: Int {
  + get { return storedValue }
  + }
  +}
  +
  +func use<T>(_ t: T) {}
  +
  func main() {
  var user_option = Options(rawValue: 123456)
  + var computed_option = ComputedOptions(rawValue: 789)
  var sdk_option_exhaustive: NSBinarySearchingOptions = [.firstEqual, .insertionIndex]
  var sdk_option_nonexhaustive = NSBinarySearchingOptions(rawValue: 257)
  var sdk_option_nonevalid = NSBinarySearchingOptions(rawValue: 12)
  - print("break here and do test") //%self.expect('frame variable user_option', substrs=['rawValue = 123456'])
  + use((user_option, computed_option, // break here
  + sdk_option_exhaustive, sdk_option_nonexhaustive,
  + sdk_option_nonevalid)) //%self.expect('frame variable user_option', substrs=['rawValue = 123456'])
  + //%self.expect('frame variable computed_option', substrs=['storedValue', '789'])
  //%self.expect('expression user_option', substrs=['rawValue = 123456'])
  //%self.expect('frame variable sdk_option_exhaustive', substrs=['[.firstEqual, .insertionIndex]'])
  //%self.expect('expression sdk_option_exhaustive', substrs=['[.firstEqual, .insertionIndex]'])
  