Overview updates: parser

[chrissimpkins]

Do not merge into master.

Working branch for the Overview document in #633

[chrissimpkins]

@rust-lang/wg-rustc-dev-guide The detailed outline for the rustc_interface, lexer, and parser are ready for review as of b3e75e8.

[mark-i-m]

This content is great ❤️! But I feel it is too detailed for the overview. We don't mention nearly so much info for any other part of the compiler, and my inclination is to say that we should move most of it to the parser/lexer chapter instead, with the overview having one bullet point on each major part of the compiler. e.g.

• low-level lexer
• high-level lexer
• parser/AST
• macro expansion, AST validation, name res, early linting

cc @rust-lang/wg-rustc-dev-guide I wonder what others think

[chrissimpkins]

No problem at all. I have a good outline now and can move it out of the Overview to start making sections in the chapter. What do you feel we should leave in the outline? One line summary and entry point?

[mark-i-m]

@chrissimpkins I posted on zulip. I would really want to see what others in the WG think and try to come a consensus about how much detail to have in the overview.

[chrissimpkins]

Sounds good. Won’t remove anything here yet.

[mark-i-m]

rebased

[mark-i-m]

Merged into #633