SI-7436 Varargs awareness for super param aliasing.

[retronym]

Don't consider a super class parameter accessor to be
an alias if it is a repeated. Parameter aliases are used
to avoid retaining redundant fields in the subclass; but
that optimization is out of the question here.

Review by @paulp

[paulp]

LGTM. I feel like there's another nearly identical ticket for this, but I can't find it so maybe not.

[retronym]

@Sciss's bug in the comments looks the same, but the main report there appears distinct.

The difference between your patch and mine is that I consider that these aren't aliases at all, whereas you consider them an alias but then discard them when deciding whether the alias can be used to elide the field. That's where I fixed a similar access related bug with the condition localTyper.context.isAccessible(sym, pre, superAccess = true).

Arguably, the access fix is in the wrong place and should be moved. I guess it depends on how you define 'alias'. I don't feel strongly enough to change it, but let me know if you have an opinion.

[paulp]

I have no strong feelings about paramaccessors.