I couldn't get generate_parser.py to work without modification
because my version of cargo-expand didn't accept a --release
argument. I assume --release isn't supported in the newest version
of this tool.
Once I did get it to run, the auto-generated file wasn't formatted
at all and was literally just a wall of unreadable tokens. It appears
we were disabling rustfmt as part of generating the file. So I
removed that and got a working generation of parser.rs!
The changes to parser.rs reflect the new auto-generated content.
I also snuck in the addition of a rustfmt::skip attribute. This
is needed to avoid rustfmt complaining about the content of this
file.