pythongh-119521: Use PyAPI_DATA, not extern, for _PyExc_IncompleteInputError (pythonGH-120955)

Author: encukou

Include/internal/pycore_pyerrors.h

@@ -168,7 +168,8 @@ void _PyErr_FormatNote(const char *format, ...);
 Py_DEPRECATED(3.12) extern void _PyErr_ChainExceptions(PyObject *, PyObject *, PyObject *);
 
 // implementation detail for the codeop module.
-extern PyTypeObject _PyExc_IncompleteInputError;
+// Exported for test.test_peg_generator.test_c_parser
+PyAPI_DATA(PyTypeObject) _PyExc_IncompleteInputError;
 #define PyExc_IncompleteInputError ((PyObject *)(&_PyExc_IncompleteInputError))
 
 #ifdef __cplusplus