Use fewer delayed bugs.

For some cases where it's clear that an error has already occurred,
e.g.:
- there's a comment stating exactly that, or
- things like HIR lowering, where we are lowering an error kind

The commit also tweaks some comments around delayed bug sites.

3 files changed, 3 insertions, 7 deletions

diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 942aae3d536..73d1d891bb9 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -323,9 +323,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     )
                 }
                 ExprKind::Yield(opt_expr) => self.lower_expr_yield(e.span, opt_expr.as_deref()),
-                ExprKind::Err => {
-                    hir::ExprKind::Err(self.dcx().span_delayed_bug(e.span, "lowered ExprKind::Err"))
-                }
+                ExprKind::Err => hir::ExprKind::Err(self.dcx().has_errors().unwrap()),
                 ExprKind::Try(sub_expr) => self.lower_expr_try(e.span, sub_expr),
 
                 ExprKind::Paren(_) | ExprKind::ForLoop { .. } => {
diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index 933372fae4e..87ed47648c8 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -1068,7 +1068,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     fn lower_block_expr_opt(&mut self, span: Span, block: Option<&Block>) -> hir::Expr<'hir> {
         match block {
             Some(block) => self.lower_block_expr(block),
-            None => self.expr_err(span, self.dcx().span_delayed_bug(span, "no block")),
+            None => self.expr_err(span, self.dcx().has_errors().unwrap()),
         }
     }
 
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 480072ce705..6b5fc014240 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -1285,9 +1285,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn lower_ty_direct(&mut self, t: &Ty, itctx: ImplTraitContext) -> hir::Ty<'hir> {
         let kind = match &t.kind {
             TyKind::Infer => hir::TyKind::Infer,
-            TyKind::Err => {
-                hir::TyKind::Err(self.dcx().span_delayed_bug(t.span, "TyKind::Err lowered"))
-            }
+            TyKind::Err => hir::TyKind::Err(self.dcx().has_errors().unwrap()),
             // Lower the anonymous structs or unions in a nested lowering context.
             //
             // ```