Rollup merge of rust-lang#107769 - compiler-errors:pointer-like, r=eholk

Rename `PointerSized` to `PointerLike`

The old name was unnecessarily vague. This PR renames a nightly language feature that I added, so I don't think it needs any additional approval, though anyone can feel free to speak up if you dislike the rename.

It's still unsatisfying that we don't the user which of {size, alignment} is wrong, but this trait really is just a stepping stone for a more generalized mechanism to create `dyn*`, just meant for nightly testing, so I don't think it really deserves additional diagnostic machinery for now.

Fixes rust-lang#107696, cc ``@RalfJung``
r? ``@eholk``

Author: matthiaskrgr

core/src/marker.rs

@@ -872,13 +872,14 @@ pub trait Destruct {}
 pub trait Tuple {}
 
 /// A marker for things
-#[unstable(feature = "pointer_sized_trait", issue = "none")]
-#[lang = "pointer_sized"]
+#[unstable(feature = "pointer_like_trait", issue = "none")]
+#[cfg_attr(bootstrap, lang = "pointer_sized")]
+#[cfg_attr(not(bootstrap), lang = "pointer_like")]
 #[rustc_on_unimplemented(
-    message = "`{Self}` needs to be a pointer-sized type",
-    label = "`{Self}` needs to be a pointer-sized type"
+    message = "`{Self}` needs to have the same alignment and size as a pointer",
+    label = "`{Self}` needs to be a pointer-like type"
 )]
-pub trait PointerSized {}
+pub trait PointerLike {}
 
 /// Implementations of `Copy` for primitive types.
 ///