Add C API to notify when tracing/profiling is enabled or disabled

Feature or enhancement

Proposal:

There is currently no way to be notified when tracing/profiling is enabled or disabled. This forces tools that want different behavior based on tracing/profiling enablement (e.g., JIT compilers) to poll on every function call, adding significant overhead.
PEP-523 established frame evaluation hooks as an officially supported extension point for JITs. However, JITs using this API have no efficient way to know when tracing/profiling is enabled and fall back to the interpreter.
I propose adding a small C API enhancement allowing callbacks to be registered when trace/profile functions are set or cleared.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-144691

Examinez PEP-523, les hooks d’évaluation des frames et les chemins existants de définition et d’effacement de la fonction de traçage/profilage ; l’issue ne nomme pas de fichiers ni de tests précis. Le travail est terminé lorsqu’une C API permet aux outils d’enregistrer des callbacks pour les changements d’activation du traçage/profilage sans polling, avec un comportement aligné sur la PR liée gh-144691.