error: `call` trait item in `fn` lang item must be a function
  --> $DIR/fn-fn_mut-call-ill-formed.rs:10:5
   |
LL |     const call: i32 = 42;
   |     ^^^^^^^^^^^^^^^^^^^^^

error: first argument of `call` in `fn_mut` lang item must be a reference
  --> $DIR/fn-fn_mut-call-ill-formed.rs:16:16
   |
LL |     fn call(i: i32, j: i32) -> i32 { i + j }
   |                ^^^

error: aborting due to 2 previous errors