MySQL - Alter Table ... Add Index. Parsing as Command

[hubg398]

Fully reproducible code snippet

ddl = """
ALTER TABLE
    `posts` ADD INDEX `posts_integer_column__index_key_index`(`integer_column__index_key`);
"""
ast = parse_one(ddl, dialect="mysql")

Official Documentation
https://dev.mysql.com/doc/refman/8.4/en/alter-table.html

Found this one today, not sure if I'm missing something. It works if we remove the index name.
Probably has few other related ones if it is indeed a bug:

1. KEY

ALTER TABLE
    `posts` ADD KEY `posts_integer_column__index_key_index`(`integer_column__index_key`);

2. UNIQUE

ALTER TABLE
    `posts` ADD UNIQUE `posts_integer_column__index_key_unique`(`integer_column__unique_key`);

Thanks