Don't treat package object's <init> methods as package members

[dwijnand]

Extends b848c57 (#7862) to all packages.

Previously when asking for dotty.tools.dotc.util.<init> we'd get a TypeError because both
LinearMap$package's and LinearSet$package's constructors have the same modification time (in the jar).

[dwijnand]

@odersky I'm reading b848c57 (#7862) as accidentally being scala package only.

[odersky]

The change is OK. For clarity I'd consider changing it like this:

      if name == nme.CONSTRUCTOR then
        NoDenotation // packages don't have constructors, even if package objects do.
      else if symbol eq defn.ScalaPackageClass then
        // revert order: search package first, then nested package objects
        val denots = super.computeMembersNamed(name)
        if denots.exists then denots
        else recur(packageObjs, NoDenotation)
      else recur(packageObjs, NoDenotation)

[odersky]

LGTM