bpo-39573: Use Py_TYPE() macro in Objects directory (GH-18392)

Replace direct access to PyObject.ob_type with Py_TYPE().
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 9115fa1..67cbc7b 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -150,7 +150,7 @@
     if (!PyLong_Check(result)) {
         PyErr_Format(PyExc_TypeError,
                      "__int__ returned non-int (type %.200s)",
-                     result->ob_type->tp_name);
+                     Py_TYPE(result)->tp_name);
         Py_DECREF(result);
         return NULL;
     }
@@ -159,7 +159,7 @@
             "__int__ returned non-int (type %.200s).  "
             "The ability to return an instance of a strict subclass of int "
             "is deprecated, and may be removed in a future version of Python.",
-            result->ob_type->tp_name)) {
+            Py_TYPE(result)->tp_name)) {
         Py_DECREF(result);
         return NULL;
     }
@@ -203,7 +203,7 @@
         if (!PyLong_Check(result)) {
             PyErr_Format(PyExc_TypeError,
                          "__index__ returned non-int (type %.200s)",
-                         result->ob_type->tp_name);
+                         Py_TYPE(result)->tp_name);
             Py_DECREF(result);
             return NULL;
         }
@@ -212,7 +212,7 @@
                 "__index__ returned non-int (type %.200s).  "
                 "The ability to return an instance of a strict subclass of int "
                 "is deprecated, and may be removed in a future version of Python.",
-                result->ob_type->tp_name))
+                Py_TYPE(result)->tp_name))
         {
             Py_DECREF(result);
             return NULL;