Auto merge of rust-lang#73176 - LeSeulArtichaut:tyctxtat-err, r=eddyb

Add `TyCtxtAt::{ty_error, ty_error_with_message}`

~~Only e2d957d was added, the rest comes from rust-lang#70551.~~
I was unsure where to put the implementation for those methods, please tell me if there is a better place for it.

Closes rust-lang#72619, ~~blocked on rust-lang#70551~~.

r? @eddyb cc @mark-i-m, maybe this should be part of rust-lang#70551? If so feel free to cherry-pick or ask me to file a PR against your fork.

src/librustc_middle/ty/context.rs

@@ -13,13 +13,14 @@ use crate::middle::stability;
 use crate::mir::interpret::{self, Allocation, ConstValue, Scalar};
 use crate::mir::{Body, Field, Local, Place, PlaceElem, ProjectionKind, Promoted};
 use crate::traits;
+use crate::ty::query::{self, TyCtxtAt};
 use crate::ty::steal::Steal;
 use crate::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, Subst, SubstsRef, UserSubsts};
 use crate::ty::TyKind::*;
 use crate::ty::{
-    self, query, AdtDef, AdtKind, BindingMode, BoundVar, CanonicalPolyFnSig, Const, ConstVid,
-    DefIdTree, ExistentialPredicate, FloatVar, FloatVid, GenericParamDefKind, InferConst, InferTy,
-    IntVar, IntVid, List, ParamConst, ParamTy, PolyFnSig, Predicate, PredicateInner, PredicateKind,
+    self, AdtDef, AdtKind, BindingMode, BoundVar, CanonicalPolyFnSig, Const, ConstVid, DefIdTree,
+    ExistentialPredicate, FloatVar, FloatVid, GenericParamDefKind, InferConst, InferTy, IntVar,
+    IntVid, List, ParamConst, ParamTy, PolyFnSig, Predicate, PredicateInner, PredicateKind,
     ProjectionTy, Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyS, TyVar,
     TyVid, TypeAndMut,
 };
@@ -2615,6 +2616,21 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
+impl TyCtxtAt<'tcx> {
+    /// Constructs a `TyKind::Error` type and registers a `delay_span_bug` to ensure it gets used.
+    #[track_caller]
+    pub fn ty_error(self) -> Ty<'tcx> {
+        self.tcx.ty_error_with_message(self.span, "TyKind::Error constructed but no error reported")
+    }
+
+    /// Constructs a `TyKind::Error` type and registers a `delay_span_bug` with the given `msg to
+    /// ensure it gets used.
+    #[track_caller]
+    pub fn ty_error_with_message(self, msg: &str) -> Ty<'tcx> {
+        self.tcx.ty_error_with_message(self.span, msg)
+    }
+}
+
 pub trait InternAs<T: ?Sized, R> {
     type Output;
     fn intern_with<F>(self, f: F) -> Self::Output