When passing args to `WP_Query::__construct` method (in this case, but creating a `new WP_Query`, this one internally executes the `WP_Query::get_posts` method and stores the result in the `WP_Query::posts` property. When calling the `WP_Query::get_posts` again, the same SQL query gets executed, and the result is again stored in the `WP_Query::posts` property.
This was introduced in [51003].
Props david.binda, jorbin.
Fixes#53280. See #53176.
Built from https://develop.svn.wordpress.org/trunk@51144
git-svn-id: http://core.svn.wordpress.org/trunk@50753 1a063a9b-81f0-0310-95a4-ce76da25c4cd
5d9ca9dc68