title: Swift beta 6 - Confusing linker error message
body: <p>I'm getting an error message from the linker when building a Swift program with Xcode 6 beta 6, targeting iOS 8.  This code compiled and ran correctly with beta 5.</p>
  
  <pre><code>Undefined symbol for architecture x86_64:
  __TFSs26_forceBridgeFromObjectiveCU__FTPSs9AnyObject_MQ__Q_", referenced from:
   __TFC8RayTrace14RayTracingPlot15drawFocalPointfS0_FT_T_ in RayTracingPlot.o
  ld: symbol(s) not found for architecture x86_64
  </code></pre>
  
  <p>Here's the code in question:</p>
  
  <pre><code>private func drawFocalPoint() {
      var attributes = Dictionary&lt;String, AnyObject&gt;()
  
      let FString: String = "F"
      let distance: CGFloat = focalDistance
  
      let centerX = CGRectGetMidX(bounds)
      let centerY = CGRectGetMidY(bounds)
  
      let circleRadius: CGFloat = 4.0
      let focalPointFrame = CGRectMake(0, 0, circleRadius * 2.0, circleRadius * 2.0)
      var path = UIBezierPath(ovalInRect: focalPointFrame)
      let color = UIColor.blackColor()
  
      let currentContext = UIGraphicsGetCurrentContext()
      CGContextSaveGState(currentContext)
      let shadowColor = UIColor(white:0, alpha:0.75).CGColor
      CGContextSetShadowWithColor(currentContext, CGSizeMake(0, 4), CGFloat(8), shadowColor)
  
      // Image F
      var imageFPath = UIBezierPath(CGPath: path.CGPath)
      let imageFTransform = CGAffineTransformMakeTranslation((centerX - distance - circleRadius),
          (centerY - circleRadius))
      imageFPath.applyTransform(imageFTransform)
      color.set()
      imageFPath.fill()
      FString.drawAtPoint(CGPointMake(centerX - distance - circleRadius, centerY + 5), withAttributes:attributes)
  
      CGContextSetShadowWithColor(currentContext, CGSizeMake(0.0, 0.0), CGFloat(0.0), nil) // Clear shadow
      CGContextRestoreGState(currentContext)
  }
  </code></pre>
  
  <p>I'd appreciate a hint about where in this code to look for the error so I can fix it.  Thank you.</p>