Expose special method lookup at Python level

Feature or enhancement

Proposal:

As noted in the review of #144420, the Python level implementation of special method lookup has heavy dependency, and we need to expose the C level function.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-144990

从 Objects/typeobject.c 第 2922-2983 行的 C 层特殊方法查找实现开始，然后阅读 PR #144420 中的讨论以及其中链接的 PR #144990。当现有查找机制在 Python 层暴露出来，且不依赖提案中描述的重量级依赖项时，即视为完成。