Support track `__slots__` object and its property in the Tier 2 optimizer

[cocolato]

Feature or enhancement

Proposal:

Currently, when the JIT optimizer encounters _LOAD_ATTR_SLOT, it creates a new unknown symbol (<!NULL>) even if the same slot was previously written in the same trace. This prevents the optimizer from:

1. Knowing the type of values loaded from slots
2. Eliminating redundant type guards
3. Performing further type-based optimizations

To achieve these optimizations, we need:

1. keep track of where code might escape
2. implement tracking and optimization for attributes of the __slots__ object

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-144145: Track nullness of properties in the Tier 2 JIT optimizer #144122
• gh-144145: Cleanups for object property tracking in JIT optimizer #144366
• gh-144145: Revert PR#144122 for performance and potential bugs. #144391

[Kaushalt2004]

i will try to review this

[Fidget-Spinner]

For future work on STORE_ATTR_HINT, please link it to #144141