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/cpython/abstract.h b/Include/cpython/abstract.h
index 4bd7b1a..76eaedf 100644
--- a/Include/cpython/abstract.h
+++ b/Include/cpython/abstract.h
@@ -246,8 +246,8 @@
 
 /* Return 1 if the getbuffer function is available, otherwise return 0. */
 #define PyObject_CheckBuffer(obj) \
-    (((obj)->ob_type->tp_as_buffer != NULL) &&  \
-     ((obj)->ob_type->tp_as_buffer->bf_getbuffer != NULL))
+    ((Py_TYPE(obj)->tp_as_buffer != NULL) &&  \
+     (Py_TYPE(obj)->tp_as_buffer->bf_getbuffer != NULL))
 
 /* This is a C-API version of the getbuffer function call.  It checks
    to make sure object has the required function pointer and issues the
@@ -315,14 +315,14 @@
 /* ==== Iterators ================================================ */
 
 #define PyIter_Check(obj) \
-    ((obj)->ob_type->tp_iternext != NULL && \
-     (obj)->ob_type->tp_iternext != &_PyObject_NextNotImplemented)
+    (Py_TYPE(obj)->tp_iternext != NULL && \
+     Py_TYPE(obj)->tp_iternext != &_PyObject_NextNotImplemented)
 
 /* === Number Protocol ================================================== */
 
 #define PyIndex_Check(obj)                              \
-    ((obj)->ob_type->tp_as_number != NULL &&            \
-     (obj)->ob_type->tp_as_number->nb_index != NULL)
+    (Py_TYPE(obj)->tp_as_number != NULL &&            \
+     Py_TYPE(obj)->tp_as_number->nb_index != NULL)
 
 /* === Sequence protocol ================================================ */