Auto merge of #73369 - RalfJung:rollup-hl8g9zf, r=RalfJung

Rollup of 10 pull requests

Successful merges:

 - #72707 (Use min_specialization in the remaining rustc crates)
 - #72740 (On recursive ADT, provide indirection structured suggestion)
 - #72879 (Miri: avoid tracking current location three times)
 - #72938 (Stabilize Option::zip)
 - #73086 (Rename "cyclone" to "apple-a7" per changes in upstream LLVM)
 - #73104 (Example about explicit mutex dropping)
 - #73139 (Add methods to go from a nul-terminated Vec<u8> to a CString)
 - #73296 (Remove vestigial CI job msvc-aux.)
 - #73304 (Revert heterogeneous SocketAddr PartialEq impls)
 - #73331 (extend network support for HermitCore)

Failed merges:

r? @ghost

3 files changed, 33 insertions, 17 deletions

diff --git a/src/librustc_trait_selection/infer.rs b/src/librustc_trait_selection/infer.rs
index 66df4fe9511..f244785b49d 100644
--- a/src/librustc_trait_selection/infer.rs
+++ b/src/librustc_trait_selection/infer.rs
@@ -90,7 +90,7 @@ pub trait InferCtxtBuilderExt<'tcx> {
     where
         K: TypeFoldable<'tcx>,
         R: Debug + TypeFoldable<'tcx>,
-        Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable;
+        Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>;
 }
 
 impl<'tcx> InferCtxtBuilderExt<'tcx> for InferCtxtBuilder<'tcx> {
@@ -118,7 +118,7 @@ impl<'tcx> InferCtxtBuilderExt<'tcx> for InferCtxtBuilder<'tcx> {
     where
         K: TypeFoldable<'tcx>,
         R: Debug + TypeFoldable<'tcx>,
-        Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable,
+        Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>,
     {
         self.enter_with_canonical(
             DUMMY_SP,
diff --git a/src/librustc_trait_selection/lib.rs b/src/librustc_trait_selection/lib.rs
index 044239b047a..ea886cd1f9e 100644
--- a/src/librustc_trait_selection/lib.rs
+++ b/src/librustc_trait_selection/lib.rs
@@ -16,7 +16,6 @@
 #![feature(in_band_lifetimes)]
 #![feature(crate_visibility_modifier)]
 #![feature(or_patterns)]
-#![feature(option_zip)]
 #![recursion_limit = "512"] // For rustdoc
 
 #[macro_use]
diff --git a/src/librustc_trait_selection/traits/error_reporting/mod.rs b/src/librustc_trait_selection/traits/error_reporting/mod.rs
index 1b72a4bf84f..d31e04cffd5 100644
--- a/src/librustc_trait_selection/traits/error_reporting/mod.rs
+++ b/src/librustc_trait_selection/traits/error_reporting/mod.rs
@@ -1747,24 +1747,41 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
 pub fn recursive_type_with_infinite_size_error(
     tcx: TyCtxt<'tcx>,
     type_def_id: DefId,
-) -> DiagnosticBuilder<'tcx> {
+    spans: Vec<Span>,
+) {
     assert!(type_def_id.is_local());
     let span = tcx.hir().span_if_local(type_def_id).unwrap();
     let span = tcx.sess.source_map().guess_head_span(span);
-    let mut err = struct_span_err!(
-        tcx.sess,
-        span,
-        E0072,
-        "recursive type `{}` has infinite size",
-        tcx.def_path_str(type_def_id)
-    );
+    let path = tcx.def_path_str(type_def_id);
+    let mut err =
+        struct_span_err!(tcx.sess, span, E0072, "recursive type `{}` has infinite size", path);
     err.span_label(span, "recursive type has infinite size");
-    err.help(&format!(
-        "insert indirection (e.g., a `Box`, `Rc`, or `&`) \
-                           at some point to make `{}` representable",
-        tcx.def_path_str(type_def_id)
-    ));
-    err
+    for &span in &spans {
+        err.span_label(span, "recursive without indirection");
+    }
+    let msg = format!(
+        "insert some indirection (e.g., a `Box`, `Rc`, or `&`) to make `{}` representable",
+        path,
+    );
+    if spans.len() <= 4 {
+        err.multipart_suggestion(
+            &msg,
+            spans
+                .iter()
+                .flat_map(|&span| {
+                    vec![
+                        (span.shrink_to_lo(), "Box<".to_string()),
+                        (span.shrink_to_hi(), ">".to_string()),
+                    ]
+                    .into_iter()
+                })
+                .collect(),
+            Applicability::HasPlaceholders,
+        );
+    } else {
+        err.help(&msg);
+    }
+    err.emit();
 }
 
 /// Summarizes information