gh-100239: specialize BINARY_OP/SUBSCR for list-slice

[iritkatriel]

Benchmarks (stats better, time unchanged):

https://github.com/faster-cpython/benchmarking-public/blob/main/results/bm-20250416-3.14.0a7%2B-c52d9d2/bm-20250416-azure-x86_64-iritkatriel-list_subscr-3.14.0a7%2B-c52d9d2-pystats.md

• Issue: Specialize long tail of binary operations using a table. #100239

[markshannon]

list_subscript/_PyList_Subscript is the general subscript function for lists. I think we want to use a more specialized function that only works for slices. i.e this code: https://github.com/python/cpython/blob/main/Objects/listobject.c#L3614-L3618

[markshannon]

The stats diff show a 50x increase in "subscr tuple slice" as a cause of specialization failure. Any idea why that might be? I can't see any reason for it.

[markshannon]

Looks good