[MacPorts] #55471: Use separate portindexes for libc++ on older systems

[MacPorts]

#55471: Use separate portindexes for libc++ on older systems
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  Reporter:  ryandesign   |      Owner:
      Type:  enhancement  |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  base         |    Version:
Resolution:               |   Keywords:
      Port:               |
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Comment (by mojca):

 I would say that your proposal makes perfect sense. Name for `portindex`
 is a much less tricky issue than the binary packages.

 I would keep the default names at their current values and would change
 the one for `libcxx` (even though: doesn't `libc++` work as folder name?),
 according to your proposal, except that I don't know if it makes any sense
 whatsoever to do `libc++` on PPC.

 It would potentially make sense to support gcc's libstdc++v3 on PPC and
 that one could be called
 ```
 PortIndex_darwin_9_libstdcxx_powerpc
 ```
 where `libstdcxx` would stand for libstdc++v3. I don't know if we have any
 explicit support for that in base though.

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Ticket URL: <https://trac.macports.org/ticket/55471#comment:2>
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