bpo-42519: Replace PyObject_MALLOC() with PyObject_Malloc() (GH-23587)

No longer use deprecated aliases to functions:

* Replace PyObject_MALLOC() with PyObject_Malloc()
* Replace PyObject_REALLOC() with PyObject_Realloc()
* Replace PyObject_FREE() with PyObject_Free()
* Replace PyObject_Del() with PyObject_Free()
* Replace PyObject_DEL() with PyObject_Free()
diff --git a/Objects/longobject.c b/Objects/longobject.c
index e0d6410..240e92a 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -131,7 +131,7 @@ _PyLong_New(Py_ssize_t size)
                         "too many digits in integer");
         return NULL;
     }
-    result = PyObject_MALLOC(offsetof(PyLongObject, ob_digit) +
+    result = PyObject_Malloc(offsetof(PyLongObject, ob_digit) +
                              size*sizeof(digit));
     if (!result) {
         PyErr_NoMemory();