[MacPorts] #56379: root5: remove +clang35 +clang36 variants

[MacPorts]

#56379: root5: remove +clang35 +clang36 variants
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  Reporter:  dbevans  |      Owner:  cjones051073
      Type:  defect   |     Status:  assigned
  Priority:  Normal   |  Milestone:
 Component:  ports    |    Version:
Resolution:           |   Keywords:
      Port:  root5    |
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Comment (by cjones051073):

 I just pushed an update for this, removing the old variants. I also
 updated the compiler whitelist to force the use of MPs clang 5.0, as this
 seems to now give better support than last time I tried. In particular it
 builds on maxOS10.13.

 We still should push users of root5 (Users or ports) to root6. However
 thinking a bit more (better) than last time it might be worth keeping
 root5 for a bit, as root6 does not work on very old OSX versions.

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Ticket URL: <https://trac.macports.org/ticket/56379#comment:9>
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