[MacPorts] #61866: base uses incorrect SDK for Big Sur 11.1 and Xcode 12.3

[MacPorts]

#61866: base uses incorrect SDK for Big Sur 11.1 and Xcode 12.3
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  Reporter:  mf2k    |      Owner:  (none)
      Type:  defect  |     Status:  new
  Priority:  Normal  |  Milestone:
 Component:  base    |    Version:  2.6.99
Resolution:          |   Keywords:
      Port:          |
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Comment (by ryandesign):

 Replying to [comment:14 cjones051073]:
 > I guess then the globbing that was added to find matching SDKs is likely
 matching both the 11.0 and 11.1 SDKs, but for some reason selecting the
 older one. If thats the case I think it should be changed to pick the
 latest match, not the oldest ?

 The current code effectively picks a random macOS 11 SDK out of all
 available 11.x SDKs. (It returns the first item of the glob, but glob does
 not return results in any particular order. HFS+ seemed to return results
 in sorted order but APFS seems not to.) I agree that we should loop over
 the results, compare them with vercmp, and return the newest one.

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Ticket URL: <https://trac.macports.org/ticket/61866#comment:16>
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