gh-94673: Add Per-Interpreter Storage for Static Builtin Types

[ericsnowcurrently]

This is the last precursor to storing tp_subclasses (and tp_weaklist) on the interpreter state for static builtin types.

Here we add per-type storage on PyInterpreterState, but only for the static builtin types. This involves the following:

• add `PyInterpreterState.types'
  • move PyInterpreterState.type_cache to it
  • add a num_builtins_initialized field
  • add a builtins field (a static array big enough for all the static builtin types)
• add _PyStaticType_GetState() to look up a static builtin type's state
• add PyTypeObject.tp_static_builtin_index (to hold the type's index into PyInterpreterState.types.builtins)

(Adding an extra field to PyTypeObject isn't ideal and I may change it to store the index somewhere else.)

• Issue: [subinterpreters] Static types incorrectly share some objects between interpreters #94673

[ericsnowcurrently]

This was split out of #94995.

[ericsnowcurrently]

For now consider PyTypeObject.tp_static_builtin_index a temporary addition. I'd like to drop it once we start storing tp_subclasses on PyInterpreterState for static builtin types. At that point we can use tp_subclasses to store the index.

[ericsnowcurrently]

I'm going to leave tp_static_builtin_index undocumented since it is temporary. If that changes then we'll document it.

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @ericsnowcurrently for commit 9f7775d 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.