Auto merge of #121142 - GuillaumeGomez:rollup-5qmksjw, r=GuillaumeGomez

Rollup of 8 pull requests

Successful merges:

 - #120449 (Document requirements for unsized {Rc,Arc}::from_raw)
 - #120505 (Fix BTreeMap's Cursor::remove_{next,prev})
 - #120672 (std::thread update freebsd stack guard handling.)
 - #121088 (Implicitly enable evex512 if avx512 is enabled)
 - #121104 (Ignore unsized types when trying to determine the size of the original type)
 - #121107 (Fix msg for verbose suggestions with confusable capitalization)
 - #121113 (Continue compilation even if inherent impl checks fail)
 - #121120 (Add `ErrorGuaranteed` to `ast::LitKind::Err`, `token::LitKind::Err`.)

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

compiler/rustc_lint/src/reference_casting.rs

@@ -207,6 +207,13 @@ fn is_cast_to_bigger_memory_layout<'tcx>(
     }
 
     let from_layout = cx.layout_of(*inner_start_ty).ok()?;
+
+    // if the type isn't sized, we bail out, instead of potentially giving
+    // the user a meaningless warning.
+    if from_layout.is_unsized() {
+        return None;
+    }
+
     let alloc_layout = cx.layout_of(alloc_ty).ok()?;
     let to_layout = cx.layout_of(*inner_end_ty).ok()?;