rustc-ap-syntax 57.0.0

Automatically published version of the package `syntax` in the rust-lang/rust repository from commit 259e4a67843d5fbe6761a5e442836d7109d72cbe

NB: This crate is part of the Rust compiler. For an overview of the compiler as a whole, see the README.md file found in librustc.

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.