[MacPorts] #58712: clang-7.0 and clang-8.0 are missing atomic builtins on i386

[MacPorts]

#58712: clang-7.0 and clang-8.0 are missing atomic builtins on i386
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  Reporter:  devernay             |      Owner:  jeremyhu
      Type:  defect               |     Status:  assigned
  Priority:  Normal               |  Milestone:
 Component:  ports                |    Version:
Resolution:                       |   Keywords:
      Port:  clang-7.0 clang-8.0  |
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Comment (by kencu):

 It is not super easy to have the clang_rt configure one way for x86_64 and
 another way for i386, as it is presently built in one go using one cmake
 configure phase and multiple arch flags. We'd have to -- I guess -- build
 clang_rt using the muniversal portgroup or something like it, and then
 configure it differently for each section.

 We can of course set up the clang i386 builds to do this, which solves one
 part of it. But +universal builds will still be missing the i386 symbols I
 believe.

 Looking for inspiration here... I could add them in manually somehow for
 i386 I guess, or turn off the intrisics completely.

-- 
Ticket URL: <https://trac.macports.org/ticket/58712#comment:7>
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