Also stop supporting `var` with initializer inside `for`.
Resolves TODO in `handle_variable.cpp`
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Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This leaves a single state for each in the expr loop. I was trying to
think through ways to have per-token states, but they felt sort of
bulky.
Note this is more verbose: but I think the long-term is going to be that
when we start wanting to add handlers, we're going to need to switch to
different names based on the token found. As a consequence, the parse
state logic will end up diverging a little, and we'll just want to align
towards boilerplate handlers.
Short-term, this opens up a path for saying that each parse node
corresponds to precisely one token in success states, and separates out
what were becoming big handler functions in check.
This is also doing the parse node split, allowing lower reliance in
formatter on the tokenized buffer (something that I may be touching more
due to import handling).
I was suggesting this because `FloatingPoint` is pretty long. `int` and
`float` should be familiar abbreviations. `unsigned` should be familiar
to developers too, but `UnsignedInt` still feels usefully clearer for
the additional chars.