Fix condition in expandPrivate

Previous condition did not take into account private static members. Their
"enclosing class" is the enclosing package, but we really want to count them
as static members of their lexical enclosing class here.

Author: odersky

compiler/src/dotty/tools/dotc/transform/ExpandPrivate.scala

@@ -74,7 +74,7 @@ class ExpandPrivate extends MiniPhase with IdentityDenotTransformer { thisPhase
   private def ensurePrivateAccessible(d: SymDenotation)(implicit ctx: Context) =
     if (isVCPrivateParamAccessor(d))
       d.ensureNotPrivate.installAfter(thisPhase)
-    else if (d.is(PrivateTerm) && !d.owner.is(Package) && d.owner != ctx.owner.enclosingClass) {
+    else if (d.is(PrivateTerm) && !d.owner.is(Package) && d.owner != ctx.owner.lexicallyEnclosingClass) {
       // Paths `p1` and `p2` are similar if they have a common suffix that follows
       // possibly different directory paths. That is, their common suffix extends
       // in both cases either to the start of the path or to a file separator character.

tests/run/i3006b.check

@@ -1,3 +1,3 @@
-Foo$$_$bar$1
-Foo$$_$bar$2
-Bar$$_$bar$1
+bar$1
+bar$2
+bar$1