Address some code reviews

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -1570,8 +1570,9 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
             format!("does not implement `{}`", trait_ref.print_only_trait_path())
         };
 
-        let mut explain_yield =
+        let mut explain_yield = |interior_span: Span,
-            |interior_span: Span, yield_span: Span, scope_span: Option<Span>| {
+                                 yield_span: Span,
+                                 scope_span: Option<Span>| {
             let mut span = MultiSpan::from_span(yield_span);
             if let Ok(snippet) = source_map.span_to_snippet(interior_span) {
                 // #70935: If snippet contains newlines, display "the value" instead
@@ -1592,35 +1593,35 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                 //    | ||_________|______|
                 //    | |__________|      await occurs here, with value maybe used later
                 //    |            has type `closure` which is not `Send`
-                    //    = note: the return type of a function must have a statically known size
+                //
                 // So, detect it and separate into some notes, like:
+                //
                 // note: future is not `Send` as this value is used across an await
                 //   --> $DIR/issue-70935-complex-spans.rs:13:9
                 //    |
                 // LL | /         baz(|| async{
                 // LL | |             foo(tx.clone());
                 // LL | |         }).await;
-                    //    | |________________^
+                //    | |________________^ first, await occurs here, with the value maybe used later...
-                    // note: first, await occurs here, with the value maybe used later
+                // note: the value is later dropped here
-                    //   --> $DIR/issue-70935-complex-spans.rs:13:9
-                    //    |
-                    // LL | /         baz(|| async{
-                    // LL | |             foo(tx.clone());
-                    // LL | |         }).await;
-                    //    | |________________^
-                    // note: ...but, the value is later dropped here
                 //   --> $DIR/issue-70935-complex-spans.rs:15:17
                 //    |
                 // LL |         }).await;
                 //    |                 ^
-                    //    = note: the return type of a function must have a statically known size
+                //
-
                 // If available, use the scope span to annotate the drop location.
                 if let Some(scope_span) = scope_span {
                     let scope_span = source_map.end_point(scope_span);
                     let is_overlapped =
                         yield_span.overlaps(scope_span) || yield_span.overlaps(interior_span);
                     if is_overlapped {
+                        span.push_span_label(
+                            yield_span,
+                            format!(
+                                "first, {} occurs here, with {} maybe used later...",
+                                await_or_yield, snippet
+                            ),
+                        );
                         err.span_note(
                             span,
                             &format!(
@@ -1628,17 +1629,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                                 future_or_generator, trait_explanation, an_await_or_yield
                             ),
                         );
-                            err.span_note(
+                        err.span_note(scope_span, &format!("{} is later dropped here", snippet));
-                                yield_span,
-                                &format!(
-                                    "first, {} occurs here, with {} maybe used later",
-                                    await_or_yield, snippet
-                                ),
-                            );
-                            err.span_note(
-                                scope_span,
-                                &format!("...but, {} is later dropped here", snippet),
-                            );
                     } else {
                         span.push_span_label(
                             yield_span,

src/test/ui/async-await/issue-70935-complex-spans.stderr

@@ -11,15 +11,8 @@ note: future is not `Send` as this value is used across an await
 LL | /         baz(|| async{
 LL | |             foo(tx.clone());
 LL | |         }).await;
-   | |________________^
+   | |________________^ first, await occurs here, with the value maybe used later...
-note: first, await occurs here, with the value maybe used later
+note: the value is later dropped here
-  --> $DIR/issue-70935-complex-spans.rs:13:9
-   |
-LL | /         baz(|| async{
-LL | |             foo(tx.clone());
-LL | |         }).await;
-   | |________________^
-note: ...but, the value is later dropped here
   --> $DIR/issue-70935-complex-spans.rs:15:17
    |
 LL |         }).await;

src/test/ui/async-await/issues/issue-65436-raw-ptr-not-send.stderr

@@ -12,13 +12,8 @@ note: future is not `Send` as this value is used across an await
   --> $DIR/issue-65436-raw-ptr-not-send.rs:14:9
    |
 LL |         bar(Foo(std::ptr::null())).await;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ first, await occurs here, with `std::ptr::null()` maybe used later...
-note: first, await occurs here, with `std::ptr::null()` maybe used later
+note: `std::ptr::null()` is later dropped here
-  --> $DIR/issue-65436-raw-ptr-not-send.rs:14:9
-   |
-LL |         bar(Foo(std::ptr::null())).await;
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...but, `std::ptr::null()` is later dropped here
   --> $DIR/issue-65436-raw-ptr-not-send.rs:14:41
    |
 LL |         bar(Foo(std::ptr::null())).await;