Move remaining functionality from ClassWorld to ClosedWorld

pkg/compiler/lib/src/universe/world_impact.dart

Index: pkg/compiler/lib/src/universe/world_impact.dart
diff --git a/pkg/compiler/lib/src/universe/world_impact.dart b/pkg/compiler/lib/src/universe/world_impact.dart
index 723a87af8bddcdc817f0589bd60adc1db38f080e..90120575b3fb147615ecce641fc69da545b4aa5a 100644
--- a/pkg/compiler/lib/src/universe/world_impact.dart
+++ b/pkg/compiler/lib/src/universe/world_impact.dart
@@ -17,7 +17,7 @@ import 'use.dart' show DynamicUse, StaticUse, TypeUse;
 ///
 /// The impact object can be computed locally by inspecting just the resolution
 /// information of that element alone. The compiler uses [Universe] and
-/// [ClassWorld] to combine the information discovered in the impact objects of
+/// [World] to combine the information discovered in the impact objects of
 /// all elements reachable in an application.
 class WorldImpact {
   const WorldImpact();