CMake build does not work on MacOS

This is a duplicate of issue #1456 (closed) which was closed without resolving the underlying issue.

When doing a CMake build on MacOS, the linking stage for gvc produces a lot of linking errors:

Undefined symbols for architecture x86_64:
  "_CL_type", referenced from:
      _graph_init in libcommon.a(input.c.o)
  "_CmdName", referenced from:
      _dotneato_usage in libcommon.a(input.c.o)
      _dotneato_args_initialize in libcommon.a(input.c.o)
  "_Concentrate", referenced from:
      _graph_init in libcommon.a(input.c.o)
  "_E_activefillcolor", referenced from:
      _emit_edge_graphics in libcommon.a(emit.c.o)
  "_E_activepencolor", referenced from:
      _emit_edge_graphics in libcommon.a(emit.c.o)
  "_E_arrowhead", referenced from:
      _graph_init in libcommon.a(input.c.o)
      _arrow_flags in libcommon.a(arrows.c.o)

etc etc… (a complete list of failures can be found in https://pastebin.com/EZnckWYi)