message: Fix a broken link in CONTRIBUTING.md
  `testsuite/support/mod.rs` is replaced at
diff: @@ -85,8 +85,8 @@ working on.
  * [Commit as you go][githelp].
  * Include tests that cover all non-trivial code. The existing tests
  in `test/` provide templates on how to test Cargo's behavior in a
  -sandbox-environment. The internal module `testsuite/support` provides a vast amount
  -of helpers to minimize boilerplate. See [`testsuite/support/mod.rs`] for an
  +sandbox-environment. The internal module `crates/cargo-test-support` provides a vast amount
  +of helpers to minimize boilerplate. See [`crates/cargo-test-support/src/lib.rs`] for an
  introduction to writing tests.
  * Make sure `cargo test` passes. If you do not have the cross-compilers
  installed locally, install them using the instructions returned by
  @@ -197,6 +197,6 @@ adding labels to triage issues:
  [I-nominated]: https://github.com/rust-lang/cargo/labels/I-nominated
  [Code of Conduct]: https://www.rust-lang.org/conduct.html
  [Discord]: https://discordapp.com/invite/rust-lang
  -[`testsuite/support/mod.rs`]: https://github.com/rust-lang/cargo/blob/master/tests/testsuite/support/mod.rs
  +[`crates/cargo-test-support/src/lib.rs`]: https://github.com/rust-lang/cargo/blob/master/crates/cargo-test-support/src/lib.rs
  [irlo]: https://internals.rust-lang.org/
  [subcommands]: https://doc.rust-lang.org/cargo/reference/external-tools.html#custom-subcommands
  