Missing SELECT output on btree_gin char, BTLess* strategy

The expected output in contrib/btree_gin/expected/char.out is wrong for the
first two SELECTs using the BTLess* strategies: they should not be empty.

    set enable_seqscan=off;

    CREATE TABLE test_char (
            i "char"
    );

    INSERT INTO test_char VALUES ('a'),('b'),('c'),('d'),('e'),('f');

    CREATE INDEX idx_char ON test_char USING gin (i);

    SELECT * FROM test_char WHERE i<'d'::"char" ORDER BY i;
    SELECT * FROM test_char WHERE i<='d'::"char" ORDER BY i;

gives

     i
    ---
    (0 rows)

     i
    ---
    (0 rows)

If Bitmap Scan is turned off, we get output, as expected:

    set enable_bitmapscan=off;
    SELECT * FROM test_char WHERE i<'d'::"char" ORDER BY i;
    SELECT * FROM test_char WHERE i<='d'::"char" ORDER BY i;

gives

     i
    ---
     a
     b
     c
    (3 rows)

     i
    ---
     a
     b
     c
     d
    (4 rows)

I tried the following and got the same results:

- Do the inserts after the CREATE INDEX.
- Create the index with fastupdate turned off: CREATE INDEX ... WITH
  (fastupdate = off).
- Reconnect (and don't forget to disable sequential scan).
- Stop and start the server: pg_ctl restart.

I'm on 15devel, but this issue appears to have been around for years.