error[E0277]: the trait bound `&[i8]: From<&[u8]>` is not satisfied
  --> $DIR/issue-71394-no-from-impl.rs:8:25
   |
LL |     let _: &[i8] = data.into();
   |                         ^^^^ the trait `From<&[u8]>` is not implemented for `&[i8]`
   |
   = help: the following other types implement trait `From<T>`:
             `[T; 10]` implements `From<(T, T, T, T, T, T, T, T, T, T)>`
             `[T; 11]` implements `From<(T, T, T, T, T, T, T, T, T, T, T)>`
             `[T; 12]` implements `From<(T, T, T, T, T, T, T, T, T, T, T, T)>`
             `[T; 1]` implements `From<(T,)>`
             `[T; 2]` implements `From<(T, T)>`
             `[T; 3]` implements `From<(T, T, T)>`
             `[T; 4]` implements `From<(T, T, T, T)>`
             `[T; 5]` implements `From<(T, T, T, T, T)>`
           and 6 others
   = note: required for `&[u8]` to implement `Into<&[i8]>`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0277`.