Make generator methods `gen_set_name` and `gen_set_qualname` thread-safe in free-threaded builds

[efimov-mikhail]

Feature or enhancement

Proposal:

When my PR was reviewed, some problem was found: #133373 (comment)
But my code on _GeneratorWrapper was simply copied from gen_set_name method.

So, it seems that there is no critical section in genobject.c at all.
But there is a possibility to change name or qualname for generator/async generator/coroutine.
IMO, some simple code (Py_BEGIN_CRITICAL_SECTION and Py_END_CRITICAL_SECTION) should be added to these two methods.

Also, function object seems to have exactly the same problem.

Linked PRs

• gh-133931: Introduce _PyObject_XSetRefDelayed to replace Py_XSETREF #134377

[xuantengh]

Also, function object seems to have exactly the same problem.

Regarding function object, there was a discussion about the lock on the performance-critical fields that will be accessed during a function call:
#129016 (review)