Rollup merge of rust-lang#139467 - compiler-errors:more-trivial-tweaks, r=oli-obk

More trivial tweaks

Found some really tiny nits when trying to find places that span tracking caused queries to be recomputed in incremental; these probably don't need a perf run b/c they're so simple.

r? oli-obk

Author: Kobzol

Diff for: compiler/rustc_hir_analysis/src/check/region.rs

@@ -446,14 +446,11 @@ fn resolve_expr<'tcx>(
         // Mark this expr's scope and all parent scopes as containing `yield`.
         let mut scope = Scope { local_id: expr.hir_id.local_id, data: ScopeData::Node };
         loop {
-            let span = match expr.kind {
-                hir::ExprKind::Yield(expr, hir::YieldSource::Await { .. }) => {
-                    expr.span.shrink_to_hi().to(expr.span)
-                }
-                _ => expr.span,
+            let data = YieldData {
+                span: expr.span,
+                expr_and_pat_count: visitor.expr_and_pat_count,
+                source: *source,
             };
-            let data =
-                YieldData { span, expr_and_pat_count: visitor.expr_and_pat_count, source: *source };
             match visitor.scope_tree.yield_in_scope.get_mut(&scope) {
                 Some(yields) => yields.push(data),
                 None => {

Diff for: compiler/rustc_hir_typeck/src/demand.rs

@@ -865,10 +865,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // `&'name Ty` -> `&'name mut Ty` or `&Ty` -> `&mut Ty`
                 vec![(
                     ty_ref.1.ty.span.shrink_to_lo(),
-                    format!(
-                        "{}mut ",
-                        if ty_ref.0.ident.span.lo() == ty_ref.0.ident.span.hi() { "" } else { " " },
-                    ),
+                    format!("{}mut ", if ty_ref.0.ident.span.is_empty() { "" } else { " " },),
                 )]
             };
             sugg.extend([

Diff for: compiler/rustc_passes/src/liveness.rs

@@ -1655,7 +1655,7 @@ impl<'tcx> Liveness<'_, 'tcx> {
                 // `&'name Ty` -> `&'name mut Ty` or `&Ty` -> `&mut Ty`
                 Some(mut_ty.ty.span.shrink_to_lo())
             };
-            let pre = if lt.ident.span.lo() == lt.ident.span.hi() { "" } else { " " };
+            let pre = if lt.ident.span.is_empty() { "" } else { " " };
             Some(errors::UnusedAssignSuggestion {
                 ty_span,
                 pre,