add FIXME for things that I couldn't find ways to trigger

Author: BoxyUwU

compiler/rustc_trait_selection/src/traits/const_evaluatable.rs

@@ -31,6 +31,7 @@ pub fn is_const_evaluatable<'tcx>(
     let tcx = infcx.tcx;
     let uv = match ct.kind() {
         ty::ConstKind::Unevaluated(uv) => uv,
+        // FIXME(generic_const_exprs): this seems wrong but I couldn't find a way to get this to trigger
         ty::ConstKind::Expr(_) => bug!("unexpected expr in `is_const_evaluatable: {ct:?}"),
         ty::ConstKind::Param(_)
         | ty::ConstKind::Bound(_, _)

compiler/rustc_trait_selection/src/traits/wf.rs

@@ -476,9 +476,10 @@ impl<'tcx> WfPredicates<'tcx> {
                                 ty::Binder::dummy(ty::PredicateKind::WellFormed(ct.into())),
                             ));
                         }
-                        // FIXME(julianknodt): need to infer any nested consts here
-                        // so walk and search recursively?
-                        ty::ConstKind::Expr(_) => unimplemented!(),
+                        // FIXME(generic_const_exprs): This seems wrong but I could not find a way to get this to trigger
+                        ty::ConstKind::Expr(_) => {
+                            bug!("checking wfness of `ConstKind::Expr` is unsupported")
+                        }
 
                         ty::ConstKind::Error(_)
                         | ty::ConstKind::Param(_)