Remove yet more output from for-loop and ? errors

Author: estebank

compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs

@@ -816,11 +816,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             &substs,
             match lang_item {
                 hir::LangItem::FuturePoll => ObligationCauseCode::AwaitableExpr,
-                hir::LangItem::IntoIterIntoIter => ObligationCauseCode::ForLoopIterator,
-                hir::LangItem::TryTraitFromResidual | hir::LangItem::TryTraitBranch => {
-                    ObligationCauseCode::QuestionMark
+                hir::LangItem::IteratorNext | hir::LangItem::IntoIterIntoIter => {
+                    ObligationCauseCode::ForLoopIterator
                 }
-                _ => traits::ItemObligation(def_id),
+                hir::LangItem::TryTraitFromOutput
+                | hir::LangItem::TryTraitFromResidual
+                | hir::LangItem::TryTraitBranch => ObligationCauseCode::QuestionMark,
             },
         );
         (Res::Def(def_kind, def_id), ty)

src/test/ui/issues/issue-33941.stderr

@@ -23,6 +23,20 @@ LL |     for _ in HashMap::new().iter().cloned() {}
    = note: required because of the requirements on the impl of `Iterator` for `Cloned<std::collections::hash_map::Iter<'_, _, _>>`
    = note: required because of the requirements on the impl of `IntoIterator` for `Cloned<std::collections::hash_map::Iter<'_, _, _>>`
 
+<<<<<<< HEAD
 error: aborting due to 2 previous errors
+=======
+error[E0271]: type mismatch resolving `<std::collections::hash_map::Iter<'_, _, _> as Iterator>::Item == &_`
+  --> $DIR/issue-33941.rs:4:14
+   |
+LL |     for _ in HashMap::new().iter().cloned() {}
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected tuple, found reference
+   |
+   = note:  expected tuple `(&_, &_)`
+           found reference `&_`
+   = note: required because of the requirements on the impl of `Iterator` for `Cloned<std::collections::hash_map::Iter<'_, _, _>>`
+
+error: aborting due to 3 previous errors
+>>>>>>> 330b90f5fc1 (Remove yet more output from `for`-loop and `?` errors)
 
 For more information about this error, try `rustc --explain E0271`.