add fixme

Author: lcnr

src/test/ui/const-generics/const_evaluatable_checked/object-safety-ok-infer-err.rs

@@ -16,6 +16,7 @@ fn use_dyn<const N: usize>(v: &dyn Foo<N>) where [u8; N + 1]: Sized {
 }
 
 fn main() {
+    // FIXME(const_evaluatable_checked): Improve the error message here.
     use_dyn(&());
     //~^ ERROR type annotations needed
 }

src/test/ui/const-generics/const_evaluatable_checked/object-safety-ok-infer-err.stderr

@@ -1,5 +1,5 @@
 error[E0284]: type annotations needed: cannot satisfy `the constant `use_dyn::<{_: usize}>::{constant#0}` can be evaluated`
-  --> $DIR/object-safety-ok-infer-err.rs:19:5
+  --> $DIR/object-safety-ok-infer-err.rs:20:5
    |
 LL | fn use_dyn<const N: usize>(v: &dyn Foo<N>) where [u8; N + 1]: Sized {
    |                                                       ----- required by this bound in `use_dyn`