shortcut lookup overload in superclasses

Author: bishabosha

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -1198,18 +1198,18 @@ class TreeUnpickler(reader: TastyReader,
                      |but could not find method `$name` (${sname.info}):
                      | - $symPart.""".stripMargin)
 
-              val denot =
+              def lookupSuper =
                 val cls = ownerTpe.classSymbol
-                if !cls.exists then NoDenotation
+                if cls.exists then
+                  cls.asClass.classDenot
+                    .findMember(name, cls.thisType, EmptyFlags, excluded=Private)
+                    .atSignature(sig, target)
                 else
-                  val clsDenot = cls.asClass.classDenot
-                  val d0 = clsDenot.findMember(name, cls.thisType, EmptyFlags, EmptyFlags).atSignature(sig, target)
-                  if !d0.symbol.exists || d0.symbol.isAccessibleFrom(prefix) then
-                    d0.asSeenFrom(prefix)
-                  else
-                    clsDenot.findMember(name, cls.thisType, EmptyFlags, excluded=Private)
-                      .atSignature(sig, target)
-                      .asSeenFrom(prefix)
+                  NoDenotation
+
+              val denot =
+                val d = ownerTpe.decl(name).atSignature(sig, target)
+                (if !d.exists then lookupSuper else d).asSeenFrom(prefix)
 
               val select = makeSelect(qual, name, denot)
               if !(owner.exists && denot.exists) && ctx.settings.YstrictTasty.value then