Use symbol equality

Author: nicolasstucki

library/src/scala/tasty/util/ShowSourceCode.scala

@@ -1168,14 +1168,14 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
 
     object RootPackage {
       def unapply(tpe: TypeOrBounds)(implicit ctx: Context): Boolean = tpe match {
-        case Type.SymRef(sym, _) => sym.fullName == "<root>" // TODO use Symbol.==
+        case Type.SymRef(sym, _) => sym == definitions.RootClass
         case _ => false
       }
     }
 
     object EmptyPackage {
       def unapply(tpe: TypeOrBounds)(implicit ctx: Context): Boolean = tpe match {
-        case Type.SymRef(sym, _) => sym.fullName == "<empty>"
+        case Type.SymRef(sym, _) => sym == definitions.EmptyPackageClass
         case _ => false
       }
     }