Nowarn public implicit val class params

[som-snytt]

Similar to explicit param.

Fixes #22662

[som-snytt]

Explanation of protected member of given class is #8397

The warning considers any such member. But adding Protected is restricted to members the user might name. That may be wrong if a macro def f = summonInline[G].T constructs a usage of the derived name in a leaky position.

[som-snytt]

So you're saying that you should only warn on private accessor, except that givens might be widened to protected so also warn about those.

The other tweak, to only widen givens that have a human name, is therefore not strictly needed for warning purposes? if you're willing to warn about protected.

[sjrd]

@Gedochao I don't fell qualified to review this. I don't understand how/why there suddenly are protected things in givens, or even how that is supposed to make them "not leak".

[som-snytt]

@sjrd me neither. I removed that bit, which also didn't have a (new) test. This is just for the hapless warning. May I beg a review?

github doesn't offer the poke widget yet. (I just read a comment from a few years ago along the lines of, if we're swamped with trivial tickets, we can't get real work done.)

[som-snytt]

@sjrd merci beaucoup.