Major fixes and new features

venv/lib/python3.12/site-packages/mypyc/lib-rt/module_shim.tmpl

@@ -0,0 +1,18 @@
+#include <Python.h>
+
+PyMODINIT_FUNC
+PyInit_{modname}(void)
+{{
+    PyObject *tmp;
+    if (!(tmp = PyImport_ImportModule("{libname}"))) return NULL;
+    Py_DECREF(tmp);
+    void *init_func = PyCapsule_Import("{libname}.init_{full_modname}", 0);
+    if (!init_func) {{
+        return NULL;
+    }}
+    return ((PyObject *(*)(void))init_func)();
+}}
+
+// distutils sometimes spuriously tells cl to export CPyInit___init__,
+// so provide that so it chills out
+PyMODINIT_FUNC PyInit___init__(void) {{ return PyInit_{modname}(); }}