bors 71cd3a926f Auto merge of #13016 - dtolnay-contrib:messagetype, r=ehuss
Handle $message_type in JSON diagnostics

### What does this PR try to resolve?

Unblocks https://github.com/rust-lang/rust/pull/115691.

Without this change, Cargo's testsuite fails in `doc::doc_message_format` and `metabuild::metabuild_failed_build_json`.

### How should we test and review this PR?

Tested with and without https://github.com/rust-lang/rust/pull/115691.

In Cargo repo: `cargo test --test testsuite`
In Rust repo: `x.py test src/tools/cargo` (separately on master and $message_type PR)
2023-11-20 15:30:57 +00:00
..
2023-11-16 11:35:21 -05:00