gh-120619: Tier 2 partial evaluator foundations

[Fidget-Spinner]

This PR sets up a tier 2 partial evaluation pass' foundations. It does the following:

1. Introduce binding-time analysis of instructions and locals.
2. Virtualized stack values (This was why we need a local slot now to indicate if the stack value is pointing to a virtualized instruction).
3. A new abstract interpreter -- one for partial evaluation.
4. Symbolic stack reification -- reconstructing the stack when we need to/hit a non-static instruction. This is done by telling the originating instruction to devirtualize itself.

As a litmus test, it does simple dead store elimination by tracking locals. For example, the code x = x is now optimized to a nop.

This is different than the previous PR at #123652. The main difference is that we create the residual in-place. By "looking backwards" at the originating instruction and marking that as virtual/non-virtual. If you want a visualization of how this will work. See Mark's talk at EuroPython 2023 here https://youtu.be/dgrtgtT-UXM?t=1198.

Also up for discussion: the generator for the partial evaluator is exactly the same as the specializer. Should I just remove it?

• Issue: Add tier 2 partial evaluation pass. #120619

[Fidget-Spinner]

@markshannon I split it out into its own files, and own symbols, so it doesn't share the type information too. This simplifies the lattice quite a bit.

[Eclips4]

Suggested change

	if (length <= 0) {
	return length;
	}

We'll anyway return length in line 310

[Eclips4]

Suggested change

	Writes the cases to partial_evaluator_cases.c.h, which is #included in Python/optimizer_analysis.c.
	Writes the cases to partial_evaluator_cases.c.h, which is #included in Python/partial_evaluator.c.

[python-cla-bot]

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[Fidget-Spinner]

I have a different approach in mind.