Issue #18408: Fix call_function() of ceval.c to handle PyTuple_New() failure

(in load_args()), ex: MemoryError.

Python/ceval.c

@@ -4171,11 +4171,16 @@ call_function(PyObject ***pp_stack, int oparg
         else {
             PyObject *callargs;
             callargs = load_args(pp_stack, na);
+            if (callargs != NULL) {
                 READ_TIMESTAMP(*pintr0);
                 C_TRACE(x, PyCFunction_Call(func,callargs,NULL));
                 READ_TIMESTAMP(*pintr1);
                 Py_XDECREF(callargs);
             }
+            else {
+                x = NULL;
+            }
+        }
     } else {
         if (PyMethod_Check(func) && PyMethod_GET_SELF(func) != NULL) {
             /* optimize access to bound methods */