For consistency, move NonNull impl to non_null.rs.

Author: kpreid

library/core/src/marker.rs

@@ -1003,7 +1003,6 @@ marker_impls! {
         {T} &mut T,
         {T} *const T,
         {T} *mut T,
-        {T} crate::ptr::NonNull<T>,
         {T: PointerLike} crate::pin::Pin<T>,
 }
 

library/core/src/ptr/non_null.rs

@@ -1548,6 +1548,10 @@ impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NonNull<U>> for NonNull<T> where T: U
 #[stable(feature = "pin", since = "1.33.0")]
 unsafe impl<T: ?Sized> PinCoerceUnsized for NonNull<T> {}
 
+#[unstable(feature = "pointer_like_trait", issue = "none")]
+#[cfg(not(bootstrap))]
+impl<T> core::marker::PointerLike for NonNull<T> {}
+
 #[stable(feature = "nonnull", since = "1.25.0")]
 impl<T: ?Sized> fmt::Debug for NonNull<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {