Move Eq instances into scala.Eq companion object?

[Blaisorblade]

Discussion after https://www.reddit.com/r/programming/comments/6elim6/announcing_dotty_012rc1_a_major_step_towards/ points out that the extra implicit instances of Eq infect the global namespace and that's undesirable — those instances are currently available for autocompletion when typing e.

Could one move them to Eq's companion object?

That might require using a different object as default instance, and maybe patching compiler special cases—such changes are included in the scope of this issue.

[odersky]

I think we could well move them to the companion object. Who wants to try that? Happy to review a PR.

[Blaisorblade]

To be sure: I can't volunteer to send PRs till I graduate.

[Blaisorblade]

Downside of moving the instances: they can't be disabled. eqAny was moved to Predef exactly so that it could be disabled (#1247), so it seems it should stay there (not sure about the name though, but I won't bikeshed over that).

EDIT: to be clear, I think eqAny should stay and valid, specific instances should move.