bpo-39573: Use Py_TYPE() macro in Python and Include directories (GH-18391)

Replace direct access to PyObject.ob_type with Py_TYPE().
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 5125a51..3fd133c 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -54,11 +54,11 @@
      PyType_FastSubclass((PyTypeObject*)(x), Py_TPFLAGS_BASE_EXC_SUBCLASS))
 
 #define PyExceptionInstance_Check(x)                    \
-    PyType_FastSubclass((x)->ob_type, Py_TPFLAGS_BASE_EXC_SUBCLASS)
+    PyType_FastSubclass(Py_TYPE(x), Py_TPFLAGS_BASE_EXC_SUBCLASS)
 
 PyAPI_FUNC(const char *) PyExceptionClass_Name(PyObject *);
 
-#define PyExceptionInstance_Class(x) ((PyObject*)((x)->ob_type))
+#define PyExceptionInstance_Class(x) ((PyObject*)Py_TYPE(x))
 
 
 /* Predefined exceptions */