Compilation failure on macOS

[Guy]

Greetings, I was trying to compile this project (the most recent 
`devel/modula-2` branch) on macOS 13.6 using GCC 11.3 (acquired from MacPorts), 
and it proceeds (seemingly) without issue for quite awhile, up until it tries 
to link with the object file `m2rte.so` where I receive:

`g++ -std=gnu++11 -g -I/opt/local/include        -fno-rtti plugin/m2rte.o 
-shared -o plugin/m2rte.so
Undefined symbols for architecture x86_64:
  "integer_zerop(tree_node const*)", referenced from:
      gimple_call_addr_fndecl(tree_node const*) in m2rte.o
  "rtegraph_init()", referenced from:
      _plugin_init in m2rte.o
  "rtegraph_finish()", referenced from:
      (anonymous namespace)::analyse_graph(void*, void*) in m2rte.o
  "rtegraph_lookup(gimple*, tree_node*, bool)", referenced from:
      (anonymous namespace)::pass_warn_exception_inevitable::execute(function*) 
in m2rte.o
…`

Quite a few more similar symbol errors are emitted for the same file before 
progress eventually halts with:

`ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
<stdout>:2190:16: warning: function 'yyinput' is not needed and will not be
      emitted [-Wunneeded-internal-declaration]
    static int yyinput (void)
               ^
make[2]: *** [plugin/m2rte.so] Error 1
make[2]: *** Waiting for unfinished jobs....
28 warnings generated.
4 warnings generated.
make[1]: *** [all-gcc] Error 2
make: *** [all] Error 2`

I saw that sometime last year someone seemed to be able to successfully compile 
the project on OSX 10.5.8 for PowerPC, though I am unsure what has exactly 
changed since then. I am certainly aware that this is quite a specific issue to 
my local environment and understand if you can’t or don’t want to help, but 
thought I would at least ask if you had any tips on why it might failing on 
this specific file/point in the compilation/link process?

I also noticed that the final error indicates it is from clang, which may 
likely be apart of the issue that I will have to look more into personally.

Thank you