Move stackref buffer to per-eval loop to reduce interp stack usage

Feature or enhancement

Proposal:

The interpreter main loop's stack usage is huge. We should try to reduce it a little. Currently, the stackref buffer takes up 10 words on 64-bit machines. We could lessen that by moving it to the heap (thread state).

This might mean slightly less perf due to worse locality and one memory indirection. So let's benchmark this to be sure.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-138116

從直譯器主迴圈開始，找出提案中提到的 stackref 緩衝區和執行緒狀態。對目前的配置和提議的配置進行基準測試，包括堆疊使用量、區域性或間接存取成本，以及效能。只有在測量結果支持這項變更時，才依照提案移動 stackref 緩衝區；完成意味著這一點；gh-138116 表示相關工作已經在進行中。