[Issue 23177] ModuleInfo is not exported on Windows

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23177

--- Comment #2 from Richard Cattermole <alphaglosined at gmail.com> ---
It was indeed as simple as adding:

```d
objmod.export_symbol(m.csym, 0);
```

to ``genModuleInfo``.

However I ran into a lot of issues in the test suite (mostly fixable, since it
just needed to know about the fact that import + export libraries were being
generated).

For the test it was as simple as adding a new module
``test/dshell/extra-files/dll/issue23177.d`` and importing it to ``mydll.d``
and ``testdll.d``.

I managed to get it down to only one test failing. Unicode symbols are part of
it ``runnable/testmodule.d``. I have no idea how to fix this particular issue,
so unfortunately my fix is on hold until that can be resolved.

--