Revert "Change TypeInference to handle super calls as direct invocations." and "Optimize needNoSuch…

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

Index: pkg/compiler/lib/src/universe/class_set.dart
diff --git a/pkg/compiler/lib/src/universe/class_set.dart b/pkg/compiler/lib/src/universe/class_set.dart
index 637fd168f1c891cd59fa934c21897837dd8384d3..2dd892ef431b5c258c62e579255556db2a4a07c4 100644
--- a/pkg/compiler/lib/src/universe/class_set.dart
+++ b/pkg/compiler/lib/src/universe/class_set.dart
@@ -461,10 +461,6 @@ class ClassSet {
     return true;
   }
 
-  Iterable<ClassHierarchyNode> get subtypeNodes {
-    return _subtypes ?? const <ClassHierarchyNode>[];
-  }
-
   /// Returns an [Iterable] of the subclasses of [cls] possibly including [cls].
   ///
   /// Subclasses are included if their instantiation properties intersect with