Currently, `evaluate()` recalculates whether the MediaQuery matches or
not, and stores it in `m_matches`, which users can query using
`matches()`. This allows us to know when the match-state changes, which
is required to fire MediaQueryList's change event.
This is a list of MediaQuery objects. Not to be confused with
`MediaQueryList`, which is concerned with firing events when a media
query's match-state changes.