Don't do ExpandPrivate checks on synthetic methods

Author: anatoliykmetyuk

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

@@ -66,7 +66,7 @@ class ExpandPrivate extends MiniPhase with IdentityDenotTransformer { thisPhase
   private def ensurePrivateAccessible(d: SymDenotation)(using Context) =
     if (isVCPrivateParamAccessor(d))
       d.ensureNotPrivate.installAfter(thisPhase)
-    else if (d.is(PrivateTerm) && !d.owner.is(Package) && d.owner != ctx.owner.lexicallyEnclosingClass && !d.is(InlineProxy)) {
+    else if (d.is(PrivateTerm) && !d.owner.is(Package) && d.owner != ctx.owner.lexicallyEnclosingClass && !d.is(InlineProxy) && !d.is(Synthetic)) {
       // 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.