[MacPorts] #58493: cctools: using clang < 5.0 as default assembler generates assembly errors in some cases

[MacPorts]

#58493: cctools: using clang < 5.0 as default assembler generates assembly errors
in some cases
----------------------+----------------------
  Reporter:  kencu    |      Owner:  jeremyhu
      Type:  defect   |     Status:  assigned
  Priority:  Normal   |  Milestone:
 Component:  ports    |    Version:
Resolution:           |   Keywords:
      Port:  cctools  |
----------------------+----------------------

Comment (by kencu):

 From that point of view, we should just use `mp-clang-5.0` for the
 assembler on all older systems, even if not installed when cctools is
 built/installed, as in the end, every older system will wind up having
 that installed, via the `cxx11 1.1 PortGroup`.

 That is very easy to do.

-- 
Ticket URL: <https://trac.macports.org/ticket/58493#comment:11>
MacPorts <https://www.macports.org/>
Ports system for macOS