Deriving `Clone` and `PartialEq` on a type containing `!` creates warnings

[WaffleLapkin]

Given the following code:

#![feature(never_type)]

#[derive(Clone, PartialEq)]
pub struct X(!);

I would expect no warnings to be emitted. Instead, both Clone and PartialEq macros emit unreachable code warnings:

warning: unreachable call
 --> src/lib.rs:3:10
  |
3 | #[derive(Clone, PartialEq)]
  |          ^^^^^ unreachable call
4 | pub struct X(!);
  |              - any code following this expression is unreachable
  |
  = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default

warning: unreachable expression
 --> src/lib.rs:4:14
  |
3 | #[derive(Clone, PartialEq)]
  |                 --------- in this derive macro expansion
4 | pub struct X(!);
  |              ^
  |              |
  |              unreachable expression
  |              any code following this expression is unreachable

[WaffleLapkin]

For enums the same happens, but only with Clone (PartialEq, Eq, PartialOrd, Ord, and Hash do not cause warnings):

#![feature(never_type)]

#[derive(Clone)]
pub enum X {
   V(!),
}

warning: unreachable call
 --> src/lib.rs:3:10
  |
3 | #[derive(Clone, PartialEq, Eq, Ord, PartialOrd, Hash)]
  |          ^^^^^ unreachable call
4 | pub enum X {
5 |    V(!),
  |      - any code following this expression is unreachable
  |
  = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default

[WaffleLapkin]

Deriving Copy makes Clone not warn.