[PATCH 0/10] MR4201: widl: Cleanup and simplify expressions.

[Rémi Bernon (＠rbernon)]

Some cleanup for expressions, sanitizing the structure a bit especially for abstract operations with multiple args.

I also found out about named bison variables, implicit (as `$token` referring to `token`), or explicit (as `$name` referring to `token[name]`). I think it would make the rules much more readable so I started using them here. My plan is to add them progressively to the rules, unless there's some good reason not to (like idk how portable they are, if that's something we should be worried about).