post_type parameter in update_post_caches() accepts more than a single post type

[DrewAPicture]

In update_post_caches(), the post_type parameter is documented as only accepting a single post type, which is inaccurate. It actually accepts a single post type, 'any' for any post type, and also an array of post types.

[spacedmonkey]

I like this @DrewAPicture !

Something I was wonder to make this clearer. Should we change this line

function update_post_caches( &$posts, $post_type = 'post', $update_term_cache = true, $update_meta_cache = true ) {

to

function update_post_caches( &$posts, $post_types = array( 'post' ), $update_term_cache = true, $update_meta_cache = true ) {

It gets converted to an array on line 7399 anyway.

I think it maybe would be clearer, if it was post types.

[DrewAPicture]

@spacedmonkey I feel like we should leave the parameter as-is. Yes we convert it to an array anyway with $ptypes but it strikes me that accepting multiples is the exception not the rule.

[peterwilsoncc]

A minor change in 58189.2.diff​ to document the parameter as string|string[].

[peterwilsoncc]

In 62799:

Cache API: Correct docs for update_post_caches() parameters.

Documents the $post_type parameter accepts both a single post type as a string or multiple post types as an array.

Props drewapicture, spacedmonkey.
Fixes #58189.