Define `PrettyHelp` class with methods for declaring different parts of help message.
Currently able to produce standard help messages as expected.
Updates chformal to use (only) the new help_v2.
Currently makes use of a global static to track the current help context, allowing register.h to live in blissful ignorance and instead rely on help_v2 implementations calling `auto *help = PrettyHelp::get_current();` and `return true;` to minimise impact on rebuilds (i.e. not requiring every source file to be recompiled).
Add `doc_string` field to `Pass` constructor
Add `docs/util/newcmdref.py` to contain command domain
Update `docs/util/cmdref.py` with `cmd:usage` and `cmd:optiongroup` for describing commands.
Functional, but WIP.
Experimental new formatting for describing passes that can be rendered into the standard help format, as well as being more amenable to smarter formatting for web documentation.
`b_width_capped` already exists for preventing arithmetic overflow, limiting the value of `b_width` to 30. This just changes the left shifts to also use it.
The caveat of incorrect results for extremely large values of `a_width` still applies, as does the improbability of that actually happening.
This fixes#4844 (or at least, the floating point exception; the circuit still isn't valid but I think that's fine).
In the current documentation, it's unclear if `result.string` serves as
an example of a string name. It is furthermore unclear what the purpose
of `result.string` is. Clarify this by adding a small explanation (and
fix a typo)
The B port is for single-bit summands. These can just as well be
represented as an additional summand on the A port (which supports
summands of arbitrary width). An upcoming `$macc_v2` cell won't be
special-casing single-bit summands in any way.
In preparation, make the following changes:
* remove the `bit_ports` field from the `Macc` helper (instead add any
single-bit summands to `ports` next to other summands)
* leave `B` empty on cells emitted from `Macc::to_cell`
