Add assert message to suggestion in lint assertions_on_constants
<!--
Thank you for making Clippy better!
We're collecting our changelog from pull request descriptions.
If your PR only updates to the latest nightly, you can leave the
`changelog` entry as `none`. Otherwise, please write a short comment
explaining your change.
If your PR fixes an issue, you can add "fixes #issue_number" into this
PR description. This way the issue will be automatically closed when
your PR is merged.
If you added a new lint, here's a checklist for things that will be
checked during review or continuous integration.
- [x] Followed [lint naming conventions][lint_naming]
- [x] Added passing UI tests (including committed `.stderr` file)
- [ ] `cargo test` passes locally
- [x] Executed `./util/dev update_lints`
- [ ] Added lint documentation
- [ ] Run `./util/dev fmt`
[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
Note that you can skip the above if you are just opening a WIP PR in
order to get feedback.
Delete this line and everything above before opening your PR -->
- [x] suggest replacing `assert!(false, "msg")` with `panic!("msg")`
- [x] extend to allow ~~variables~~ any expression for `"msg"`
- ~~suggest replacing `assert!(false, "msg {}", "arg")` with `panic!("msg {}", "arg")`~~
changelog: add assert message to suggestion in lint assertions_on_constants
Work towards fixing: #3575
d97fbdbb42