docs: Missing @return for WP_Comment_Query::get_comment_ids()

[birgire]

The inline documentation for WP_Comment_Query::get_comment_ids() is missing the @return description.

There are two return cases:

• (int) with the count query variable as true
• (array) for the comment ids

See here:

https://core.trac.wordpress.org/browser/tags/4.9/src/wp-includes/class-wp-comment-query.php#L889

We can e.g. look into WP_Site_Query::get_site_ids() for a similar case.

Good-first-bug?

References:

https://core.trac.wordpress.org/browser/tags/4.9/src/wp-includes/class-wp-comment-query.php#L468

https://core.trac.wordpress.org/browser/tags/4.9/src/wp-includes/class-wp-site-query.php#L318

[chetan200891]

Created patch to add @return for WP_Comment_Query::get_comment_ids()

[SergeyBiryukov]

In 42376:

Docs: Add missing @return entry for WP_Comment_Query::get_comment_ids().

Props chetan200891, birgire.
Fixes #42795.