Address review comments

Author: odersky

compiler/src/dotty/tools/dotc/core/SymDenotations.scala

@@ -863,7 +863,7 @@ object SymDenotations {
     /** The module implemented by this module class, NoSymbol if not applicable. */
     final def sourceModule(implicit ctx: Context): Symbol = myInfo match {
       case ClassInfo(_, _, _, _, selfType) if this is ModuleClass =>
-        def sourceOfSelf(tp: Any): Symbol = tp match {
+        def sourceOfSelf(tp: TypeOrSymbol): Symbol = tp match {
           case tp: TermRef => tp.symbol
           case tp: Symbol => sourceOfSelf(tp.info)
           case tp: RefinedType => sourceOfSelf(tp.parent)

compiler/src/dotty/tools/dotc/typer/Implicits.scala

@@ -525,7 +525,8 @@ trait ImplicitRunInfo { self: Run =>
               for (parent <- cls.classParents; ref <- iscopeRefs(tp.baseType(parent.classSymbol)))
                 addRef(ref)
             }
-            if (tp.widen.typeSymbol.isOpaqueAlias) addCompanionOf(tp.widen.typeSymbol)
+            val underlyingTypeSym = tp.widen.typeSymbol
+            if (underlyingTypeSym.isOpaqueAlias) addCompanionOf(underlyingTypeSym)
             else tp.classSymbols(liftingCtx).foreach(addClassScope)
           case _ =>
             for (part <- tp.namedPartsWith(_.isType)) comps ++= iscopeRefs(part)