By forcing all clause keys to be strings, we make it possible to use strict
comparison when validating values of 'orderby' as passed to `WP_Query`. This
eliminates situations where the presence of numeric clause keys could result
in an improperly validated 'orderby' value.
Props nikolov.tmw.
Fixes#32937.
git-svn-id: https://develop.svn.wordpress.org/trunk@34090 602fd350-edb4-49c9-b593-d223f7449a82
Creates:
`class-wp-meta-query.php`
`meta-functions.php`
`meta.php` contains only top-level code. Class file only contains the class. Functions file only contains functions.
See #33413.
git-svn-id: https://develop.svn.wordpress.org/trunk@33761 602fd350-edb4-49c9-b593-d223f7449a82