When Mojave was in beta we made it so that High Sierra bottles would
automatically be used on Mojave. Let's make this the default in general:
older bottles will be used on newer versions of macOS when a newer
bottle is not available.
This should make it easier for taps to bottle single versions of bottles
which will work more widely and to give us breathing room whenever a new
version of macOS is released.
Currently this only applies to the `wine` formula which will have the
`or_later` removed in a Homebrew/homebrew-core PR.
Question: should we use an `odeprecated` for the use of `or_later`?
This is the (partially) documented public API for Homebrew.
The main class you should look at is the {Formula} class (and classes linked from there). That's the class that's used to create Homebrew formulae (i.e. package descriptions). Assume anything else you stumble upon is private.