[MacPorts] #39975: root: Add --enable-cxx11 when using libc++ (was: root: Add --enable-cxx11 for some variants)

[MacPorts]

#39975: root: Add --enable-cxx11 when using libc++
--------------------------+------------------------
  Reporter:  jfcaron@…    |      Owner:  jeremyhu@…
      Type:  enhancement  |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:  2.2.0
Resolution:               |   Keywords:
      Port:  root         |
--------------------------+------------------------

-- 
Ticket URL: <https://trac.macports.org/ticket/39975#comment:11>
MacPorts <http://www.macports.org/>
Ports system for OS X