[MacPorts] #57412: clang ports: add runtime dependency on cctools

[MacPorts]

#57412: clang ports: add runtime dependency on cctools
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  Reporter:  ryandesign                          |      Owner:  (none)
      Type:  defect                              |     Status:  new
  Priority:  Normal                              |  Milestone:
 Component:  ports                               |    Version:
Resolution:                                      |   Keywords:
      Port:  clang-3.9, clang-4.0, clang-5.0,    |
  clang-6.0, clang-7.0, clang-devel              |
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Comment (by kencu):

 looking at this ticket [ticket:53159] that was referenced in a block
 above, it looks like we should require cctools on Mountain Lion as well.
 So I guess you're right, we should just change depends_build to
 depends_lib as you mentioned [ticket:57412#comment:9] or we'll just be
 back here in no time to do it.

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Ticket URL: <https://trac.macports.org/ticket/57412#comment:16>
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