[MacPorts] #52776: clang-3.8 upgrade to 3.8.1_4 build fails

[MacPorts]

#52776: clang-3.8 upgrade to 3.8.1_4 build fails
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  Reporter:  murrayE    |      Owner:  jeremyhu
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.3.4
Resolution:             |   Keywords:
      Port:  clang-3.8  |
------------------------+----------------------

Comment (by jeremyhu):

 Did you muck you your Availability.h?  `__SWIFT_UNAVAILABLE_MSG` is
 declared in
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include/Availability.h

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Ticket URL: <https://trac.macports.org/ticket/52776#comment:3>
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