Bug in create type when missed the comma between element list

Hi team!

I found this bug in the create type command. If you miss the comma
between the elements, the command doesn't fail; it runs and concatenates
the elements.

I detected the problem in v14.4, and it is alive in v17.

pglatest$ psql -h 127.0.0.1 -p 55532
Password for user daf:
Time: 0.481 ms
psql (16.4 (Ubuntu 16.4-1.pgdg24.04+2), server 17.0 (Debian
17.0-1.pgdg120+1))
WARNING: psql major version 16, server major version 17.
         Some psql features might not work.
Type "help" for help.

u: daf db: daf # CREATE TYPE test_enum AS ENUM(
    'one'
    'two',
    'three',
    'four'
);
CREATE TYPE
Time: 12.242 ms
u: daf db: daf # \dt+
Did not find any relations.
u: daf db: daf # \dT+
                                       List of data types
 Schema |   Name    | Internal name | Size | Elements | Owner | Access
privileges | Description
--------+-----------+---------------+------+----------+-------+-------------------+-------------
 public | test_enum | test_enum     | 4    | onetwo  +| daf
|                   |
        |           |               |      | three   +|
|                   |
        |           |               |      | four     |
|                   |
(1 row)

u: daf db: daf #

maybe, some of you can help me to report it properly.

Thank you,
Diego.