Running the https://hg.python.org/benchmarks suite against this change (edited to not have the warning about PyTupleObject* vs PyObject* types) I see no repeatably significant benefits and one that is consistently a few percent slower no matter how many times I run it: nbody.

### nbody ###
Min: 0.226902 -> 0.236582: 1.04x slower
Avg: 0.231973 -> 0.238949: 1.03x slower
Significant (t=-11.98)
Stddev: 0.00507 -> 0.00286: 1.7751x smaller

That seems odd to me, but _might_ be related to the additional call overhead. Regardless, I don't think this patch is really an optimization.