BUG #19417: '\dD' fails to list user-defined domains that shadow built-in type names (e.g., 'numeric')

The following bug has been logged on the website:

Bug reference: 19417
Logged by: yuanchao zhang
Email address: zhangyc0706(at)gmail(dot)com
PostgreSQL version: 18.2
Operating system: windows 10
Description:

Hi,
I created a domain object named `numeric` using the following SQL:
`CREATE DOMAIN numeric AS NUMERIC(12,2) DEFAULT 0 CHECK (VALUE >= 0);`
After executing this SQL, it indicated that the domain was created
successfully.
However, when I executed `\dD` in psql, I found that the domain I just
created could not be displayed.
Therefore, I queried `pg_type` using the following statement:
`SELECT
n.nspname AS schema_name,
t.typname AS domain_name,
pg_catalog.format_type(t.typbasetype, t.typtypmod) AS base_type,
t.typnotnull AS not_null,
t.typdefault AS default_value,
t.typtype
FROM pg_catalog.pg_type t
JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace
WHERE t.typtype = 'd'
ORDER BY schema_name, domain_name;`
The execution result of this SQL statement shows the domain object I just
created.
I then created a domain using a different name, as shown in the following
SQL:
`CREATE DOMAIN numeric_t1 AS NUMERIC(12,2) DEFAULT 0 CHECK (VALUE >= 0);`
After executing the SQL, I found that this domain could be shown both in
`pg_type` and through a `\dD` query.
Of course, I know that using the name numeric as the domain name isn't
particularly reasonable,
but I didn't receive any prompts during the creation process.
Therefore, I think that since the creation was successful, it should be
displayed via `\dD`.
Because I checked the documentation regarding the use of '\dD', and there
was no explanation for this special case.

Thanks.