BUG #17584: SQL crashes PostgreSQL when using ICU collation

The following bug has been logged on the website:

Bug reference: 17584
Logged by: James Inform
Email address: james(dot)inform(at)pharmapp(dot)de
PostgreSQL version: 14.5
Operating system: Linux / Mac
Description:

This bug appears in PG up to 14.5.

I have attached a data file in 7z format. Please extract the "data..csv"
from it and run the following statements in a newly created database on
PostgreSQL 14.x.

-- 1. Create collation and implizit cast
create collation mycol from "de-DE-x-icu";
create cast (varchar as integer) with inout as implicit;

-- 2. Create table
create table testtab (
a1 text not null collate "mycol",
b2 text not null collate "mycol",
c3 text not null collate "mycol",
d4 varchar(6) null collate "mycol",
e5 varchar(2) null collate "mycol",
f6 varchar(3) null collate "mycol",
g7 varchar(10) null collate "mycol",
h8 varchar(10) null collate "mycol",
i9 text null collate "mycol",
j10 text null collate "mycol",
k11 varchar(10) null collate "mycol",
l12 text null collate "mycol",
m13 varchar(10) null collate "mycol",
n14 varchar(500) null collate "mycol",
o15 varchar(80) null collate "mycol",
p16 varchar(80) null collate "mycol",
q17 varchar(10) null collate "mycol",
r18 varchar(60) null collate "mycol",
s19 varchar(10) null collate "mycol",
t20 varchar(10) null collate "mycol",
u21 text null collate "mycol",
v22 varchar(1) null collate "mycol",
w23 varchar(250) null collate "mycol",
x24 varchar(1000) null collate "mycol",
y25 varchar(1000) null collate "mycol",
z26 varchar(1000) null collate "mycol",
a27 varchar(1000) null collate "mycol",
b28 varchar(1000) null collate "mycol",
c29 varchar(1000) null collate "mycol",
d30 varchar(1000) null collate "mycol",
e31 varchar(1000) null collate "mycol",
f32 varchar(1000) null collate "mycol",
g33 int8 null,
h34 varchar(2) null collate "mycol",
i35 varchar(2) null collate "mycol",
j36 varchar(2) null collate "mycol",
k37 varchar(250) null collate "mycol",
l38 varchar(250) null collate "mycol",
m39 varchar(2) null collate "mycol",
n40 timestamptz null,
o41 timestamptz null,
p42 int8 null,
q43 int8 null,
r44 int8 not null,
constraint ak_1 unique (r44),
constraint pk_1 primary key (a1)
)
;

-- 3. Load data into table
copy testtab from '{PATH_TO_YOUR_FILE}/data.csv' csv header;

-- 4. Create index and analyze table
create index on testtab using btree (i9);
analyze testtab;

-- ERROR
-- 5. This is where the error occurs
-- ERROR: could not find block containing chunk 0x
select count(*) from
(
select vou_d.* from
(
select
r44,
i9,
j10,
n14
from
testtab
) vou_d
order by i9 asc, j10 asc
) a
;