Auto merge of rust-lang#104370 - matthiaskrgr:rollup-c3b38sm, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang#103996 (Add small clarification around using pointers derived from references)
 - rust-lang#104315 (Improve spans with `use crate::{self}`)
 - rust-lang#104320 (Use `derive_const` and rm manual StructuralEq impl)
 - rust-lang#104357 (add is_sized method on Abi and Layout, and use it)
 - rust-lang#104365 (Add x tool to triagebot)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

src/stacked_borrows/mod.rs

@@ -1053,7 +1053,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 // pointers we need to retag, so we can stop recursion early.
                 // This optimization is crucial for ZSTs, because they can contain way more fields
                 // than we can ever visit.
-                if !place.layout.is_unsized() && place.layout.size < self.ecx.pointer_size() {
+                if place.layout.is_sized() && place.layout.size < self.ecx.pointer_size() {
                     return Ok(());
                 }