The latest rename plan: `delegate`

For those following the ongoing discussions about what term to use in Dotty for the concept currently called implicit, I’ll call your attention to this PR from today, which tries out the term delegate.

I don’t have a strong opinion about it myself yet — it doesn’t strike me as an absolute win, but I think I like it a little more than implied. Y’all may want to roll it over in your minds; I’m sure we’ll be discussing it on Scala Contributors before long.

(And I’d urge folks to keep an open mind. So far, I haven’t seen any slam-dunk right answers, and it’s worth continuing to prod at this to see what seems to work best, since it’s going to be pretty important in Scala 3.)