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.