error: generic `Self` types are currently not permitted in anonymous constants
  --> $DIR/issue-56445-2.rs:7:38
   |
LL |     fn lfn_contents(&self) -> [char; Self::LFN_FRAGMENT_LEN] { loop { } }
   |                                      ^^^^
   |
note: not a concrete type
  --> $DIR/issue-56445-2.rs:4:10
   |
LL | impl<'a> OnDiskDirEntry<'a> {
   |          ^^^^^^^^^^^^^^^^^^

error: aborting due to previous error