Add lint for `panic!(123)` which is not accepted in Rust 2021. This extends the `panic_fmt` lint to warn for all cases where the first argument cannot be interpreted as a format string, as will happen in Rust 2021. It suggests to add `"{}",` to format the message as a string. In the case of `std::panic!()`, it also suggests the recently stabilized `std::panic::panic_any()` function as an alternative. It renames the lint to `non_fmt_panic` to match the lint naming guidelines.  This is part of #80162. r? ```@estebank```