when we know that the rewrite_args are NULL

                                origin/rewritable~:   origin/rewritable:
           django_template3.py             2.7s (4)             2.7s (4)  -1.3%
                 pyxl_bench.py             2.2s (4)             2.2s (4)  -1.7%
     sqlalchemy_imperative2.py             2.7s (4)             2.6s (4)  -2.4%
                       geomean                 2.5s                 2.5s  -1.8%