* `misc/__init__.py`:
* checks if there's a `yosys-abc` in the same directory - if yes, sets the variable `sys._pyosys_abc`
* checks if there's a `share` in the same directory - if yes, sets the variable `sys._pyosys_share_dirname`
* `yosys.cc::init_share_dirname`: check for `sys._pyosys_share_dirname`, use it at the highest priority if Python is enabled
* `yosys.cc::init_abc_executable_name`: check for `sys._pyosys_abc`, use it at at the highest priority if Python is enabled
* `Makefile`: add new target, `share`, to only create the extra targets
* `setup.py`: compile libyosys.so, yosys-abc and share, and copy them all as part of the pyosys build
* `test/arch/ecp5/add_sub.py`: ported `add_sub.ys` to Python to act as a test for the share directory and abc with Python wheels, used in CI
Since `docs/prep` is a prerequisite of `docs`, and should be the *only* prerequisite, calling `make docs` could end up hiding a problem with files missing from the uploaded artifact. Instead, call `make` from the docs directory which should be closer to what will run on RTDs.
* wheel versions now replace `+` with `.post` to match spec at https://packaging.python.org/en/latest/specifications/version-specifiers/
* CI updates:
* Bump action versions
* Disabled Windows for now and documented why
* Added a new job to upload all wheels
* Added new variable, `PYPI_INDEX`: fallback 'https://pypi.org/' if unset
* Added new secret, `PYPI_TOKEN`
* .editorconfig now uses 2 spaces for YML (it kept setting mine to tabs
and GitHub Actions doesn't like that)
* Update manylinux images
* FFI now built as a per-platform static library
* Explicitly set minimum macOS deployment target, use clang on macOS
* Try enabling Windows (as an experiment)
* Disable aarch64-linux, aarch64-windows
* Created `setup.py`: Python package manifest to build `pyosys` wheels with a custom extension to build and include `libyosys.so` using Make
* `.gitignore`: Added byproducts of the Python wheel build process
* `Makefile`: Added `-undefined dynamic_lookup` to `libyosys.so` so missing symbols can be resolved by importing into a Python interpreter
* `kernel/yosys.cc`: Gated `PyImport_AppendInittab` with `!Py_IsInitialized`; as of Python 3.12, the interpreter is already initialized and `PyImport_AppendInittab` would cause an exception to be raised
* Created `wheels.yml`: CI workflow for building wheels for CPython on:
* Linux (glibc, musl) and Darwin
* x86-64 and arm64
