Support getters and setters in Argument Clinic

[colesbury]

Feature or enhancement

In the C API, getters and setters are implemented using PyGetSetDef. Argument Clinic doesn't currently support writing getters and setters, probably because they are pretty straightforward to write manually -- there's not much argument parsing to be done.

Argument Clinic now supports the @critical_section directive, which avoids a bunch of boilerplate code when making things thread-safe with the --disable-gil builds. It would be helpful if Argument Clinic supported getters/setters so that we could avoid the critical section boilerplate in getters and setters as well.

Linked PRs

• gh-112205: Support @getter annotation from AC #112396
• gh-112205: Update stringio module to use AC for the thread-safe #112549
• gh-112205: Support @setter annotation from AC #112922
• gh-112205: Update textio module to use @getter as possible. #113095
• gh-112205: Support docstring for @getter #113160
• gh-112205: Require @getter and @setter to be methods #113278

[colesbury]

cc @aisk (who brought up this issue in #112116 (comment)) and @erlend-aasland for feedback

[corona10]

Another example that needs this feature: #112298

[corona10]

@colesbury @erlend-aasland @AlexWaygood
(Just for example)
What about following DSL for name setter / getter case?
It looks similar to Java lombok annotation :(

/*[clinic input] 
@setter
@getter
@critical_section
_io._Buffered.name
[clinic start generated code]*/