- Generalize the syntax for the type of a stack effect to allow a trailing `*`,
so we can declare something as e.g. `PyCodeObject *`.
- When generating assignments for stack effects,
the type of the value on the stack should be the default (i.e., `PyObject *`)
even when the variable copied to/from it has a different type,
so that an appropriate cast is generated
However, not when the variable is an array --
then the type is taken from the variable (as it is always `PyObject **`).
Introducing a new file, stacking.py, that takes over several responsibilities related to symbolic evaluation of push/pop operations, with more generality.
This mostly extracts a whole bunch of stuff out of generate_cases.py into separate files, but there are a few other things going on here.
- analysis.py: `Analyzer` etc.
- instructions.py: `Instruction` etc.
- flags.py: `InstructionFlags`, `variable_used`, `variable_used_unspecialized`
- formatting.py: `Formatter` etc.
- Rename parser.py to parsing.py, to avoid conflict with stdlib parser.py
- Blackify most things
- Fix most mypy errors
- Remove output filenames from Generator state, add them to `write_instructions()` etc.
- Fix unit tests