bpo-42519: Replace PyMem_MALLOC() with PyMem_Malloc() (GH-23586)

No longer use deprecated aliases to functions:

* Replace PyMem_MALLOC() with PyMem_Malloc()
* Replace PyMem_REALLOC() with PyMem_Realloc()
* Replace PyMem_FREE() with PyMem_Free()
* Replace PyMem_Del() with PyMem_Free()
* Replace PyMem_DEL() with PyMem_Free()

Modify also the PyMem_DEL() macro to use directly PyMem_Free().
diff --git a/Python/traceback.c b/Python/traceback.c
index 99b63af..708678f 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -419,12 +419,12 @@ _Py_DisplaySourceLine(PyObject *f, PyObject *filename, int lineno, int indent)
     if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
         Py_DECREF(io);
         Py_DECREF(binary);
-        PyMem_FREE(found_encoding);
+        PyMem_Free(found_encoding);
         return 0;
     }
     fob = _PyObject_CallMethodId(io, &PyId_TextIOWrapper, "Os", binary, encoding);
     Py_DECREF(io);
-    PyMem_FREE(found_encoding);
+    PyMem_Free(found_encoding);
 
     if (fob == NULL) {
         PyErr_Clear();