gh-115999: Add free-threaded specialization for COMPARE_OP

[Yhg1s]

Add free-threaded specialization for COMPARE_OP, and tests for COMPARE_OP specialization in general. This relies on thread-local bytecode and atomic operations to update the counters and bytecode, which are single operations.

• Issue: Make the specializing interpreter thread-safe in --disable-gil builds #115999

[mpage]

LGTM! Please add a short explanation of why the specialized instructions are thread-safe to either the pull request or the commit (when it's merged).

[markshannon]

The approach looks sound, but the test will need moving and should not rely on specific sequences of instructions.

[bedevere-app]

When you're done making the requested changes, leave the comment: I have made the requested changes; please review again.

[Yhg1s]

PTAL.

[Yhg1s]

PTAL.

Sorry, that's Google for:

I have made the requested changes; please review again.

[bedevere-app]

Thanks for making the requested changes!

@markshannon, @mpage: please review the changes made to this pull request.

[mpage]

LGTM. I queued benchmark runs for both the free-threaded and default builds for this PR. Let's wait until we have the results before merging this.

[mpage]

Performance doesn't look like a blocker:

• Default build looks neutral
• Free-threaded build looks neutral to slightly positive

[Yhg1s]

@markshannon All your concerns should have been addressed, do you want to take another look?

[corona10]

lgtm

[corona10]

@mpage, @Yhg1s I think that it's okay to merge this PR at this moment :)

[Yhg1s]

@mpage, @Yhg1s I think that it's okay to merge this PR at this moment :)

Well, not according to GitHub's UI :)

I want to give Mark the chance to review it again before I merge it, and a week and a half is not a long time when dealing with what is effectively a volunteer workforce :)