update to syn-1.0.102 This update removes the only `.gitignore` found in `rustc-src`: vendor/syn/tests/.gitignore vendor/syn-1.0.91/tests/.gitignore vendor/syn-1.0.95/tests/.gitignore To check-in `rustc-src` for hermetic builds in environments with restrictive `.gitignore` policies, one has to remove these `tests/.gitignore` and patch the respective `.cargo-checksum.json`.`syn` >1.0.101 includes dtolnay/syn@3c49303bed7a, which removes its `tests/.gitignore`. Now the `syn` crates.io package has no `.gitignore`. [`rustc-src`'s `vendor`][] is produced from the root `Cargo.toml`, `src/tools/rust-analyzer/Cargo.toml`, `compiler/rustc_codegen_cranelift/Cargo.toml`, and `src/bootstrap/Cargo.toml`. `rustc_codegen_cranelift` does not use `syn`. [`rustc-src`'s `vendor`]: https://github.com/rust-lang/rust/blob/c0784109daa0/src/bootstrap/dist.rs#L934-L940 This was produced with: cargo update --package syn --precise 1.0.102 \ cargo update --package syn --precise 1.0.102 \ --manifest-path src/tools/rust-analyzer/Cargo.toml cargo update --package syn --precise 1.0.102 \ --manifest-path src/bootstrap/Cargo.toml