Issue #26146: remove useless code

obj2ast_constant() code is baesd on obj2ast_object() which has a special case
for Py_None. But in practice, we don't need to have a special case for
constants.

Issue noticed by Joseph Jevnik on a review.

Parser/asdl_c.py

@@ -874,13 +874,6 @@ static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
 
 static int obj2ast_constant(PyObject* obj, PyObject** out, PyArena* arena)
 {
-    if (obj == Py_None || obj == Py_True || obj == Py_False) {
-        /* don't increment the reference counter, Constant uses a borrowed
-         * reference, not a strong reference */
-        *out = obj;
-        return 0;
-    }
-
     if (obj) {
         if (PyArena_AddPyObject(arena, obj) < 0) {
             *out = NULL;

Python/Python-ast.c

@@ -753,13 +753,6 @@ static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
 
 static int obj2ast_constant(PyObject* obj, PyObject** out, PyArena* arena)
 {
-    if (obj == Py_None || obj == Py_True || obj == Py_False) {
-        /* don't increment the reference counter, Constant uses a borrowed
-         * reference, not a strong reference */
-        *out = obj;
-        return 0;
-    }
-
     if (obj) {
         if (PyArena_AddPyObject(arena, obj) < 0) {
             *out = NULL;