Rollup merge of #120020 - oli-obk:long_const_eval_err_taint, r=compiler-errors

Gracefully handle missing typeck information if typeck errored

fixes #116893

I created some logs and the typeck of `fn main` is exactly the same, no matter whether the constant's body is what it is, or if it is replaced with `panic!()`. The latter will cause the ICE not to be emitted though. The reason for that is that we abort compilation if *errors* were emitted, but not if *lint errors* were emitted. This took me way too long to debug, and is another reason why I would have liked https://github.com/rust-lang/compiler-team/issues/633

compiler/rustc_hir_typeck/src/expr.rs

@@ -1526,13 +1526,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         self.check_repeat_element_needs_copy_bound(element, count, element_ty);
 
-        self.register_wf_obligation(
-            Ty::new_array_with_const_len(tcx, t, count).into(),
-            expr.span,
-            traits::WellFormed(None),
-        );
+        let ty = Ty::new_array_with_const_len(tcx, t, count);
 
-        Ty::new_array_with_const_len(tcx, t, count)
+        self.register_wf_obligation(ty.into(), expr.span, traits::WellFormed(None));
+
+        ty
     }
 
     fn check_repeat_element_needs_copy_bound(

compiler/rustc_passes/src/dead.rs

@@ -128,7 +128,10 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
         if let Some(def_id) = self.typeck_results().type_dependent_def_id(id) {
             self.check_def_id(def_id);
         } else {
-            bug!("no type-dependent def for method");
+            assert!(
+                self.typeck_results().tainted_by_errors.is_some(),
+                "no type-dependent def for method"
+            );
         }
     }