Developer tooling for `marco-core`. None of these crates are published to
crates.io (`publish = false`).
Each tool is a standalone crate with its own `Cargo.toml`. Build from the
repo root using `--manifest-path`:
```bash
cargo build --manifest-path tools/marco-ast/Cargo.toml
cargo build --manifest-path tools/perf-lab/Cargo.toml --release
```
```bash
cargo test --manifest-path tools/perf-lab/Cargo.toml --test extension_spec_it
cargo test --manifest-path tools/marco-ast/Cargo.toml
```