rustc-ap-syntax 417.0.0

Automatically published version of the package `syntax` in the rust-lang/rust repository from commit 9f91bee03f3eea93285330354dda54706028671c The publishing script for this crate lives at: https://github.com/alexcrichton/rustc-auto-publish

The syntax crate contains those things concerned purely with syntax – that is, the AST ("abstract syntax tree"), parser, pretty-printer, lexer, macro expander, and utilities for traversing ASTs.

For more information about how these things work in rustc, see the rustc guide: