title: Omit Swift from Objective-C header
body: <p>I have created an extension to <code>DispatchQueue</code> in Xcode 8 / Swift 3, and as I also have Objective-C code which coexists with swift the extension is included in the Objective-C header as <code>@interface OS_dispatch_queue</code>. This causes an error as <code>OS_dispatch_queue</code> is a protocol not class. Until this bug is fixed, is there any way I can exclude the extension from the Objective-C header?</p>
  
  <p><a href="http://www.filedropper.com/test_5" rel="nofollow">Example project</a></p>