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>`:
             <&'input [u8] as From<gimli::read::endian_slice::EndianSlice<'input, Endian>>>
             <[T; 10] as From<(T, T, T, T, T, T, T, T, T, T)>>
             <[T; 11] as From<(T, T, T, T, T, T, T, T, T, T, T)>>
             <[T; 12] as From<(T, T, T, T, T, T, T, T, T, T, T, T)>>
             <[T; 1] as From<(T,)>>
             <[T; 2] as From<(T, T)>>
             <[T; 3] as From<(T, T, T)>>
             <[T; 4] as From<(T, T, T, T)>>
           and 7 others
   = note: required for `&[u8]` to implement `Into<&[i8]>`

error: aborting due to previous error

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