warning: anonymous parameters are deprecated and will be removed in the next edition.
  --> $DIR/lint-anon-param-edition.rs:18:12
   |
LL |     fn foo(u8);
   |            ^^ help: Try naming the parameter or explicitly ignoring it: `_: u8`
   |
   = note: #[warn(anonymous_parameters)] on by default
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>