Revert "Revert "Build new IR for functions returning a constant.""

sdk/lib/_internal/compiler/implementation/inferrer/type_graph_nodes.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of type_graph_inferrer;
 
 /**
  * Common class for all nodes in the graph. The current nodes are:
  *
  * - Concrete types
@@ skipping 167 matching lines @@
   Iterator<TypeInformation> get iterator => assignments.keys.iterator;
   Iterable<TypeInformation> where(Function f) => assignments.keys.where(f);
 
   bool contains(TypeInformation info) => assignments.containsKey(info);
 
   String toString() => assignments.keys.toList().toString();
 }
 
 /**
  * A node representing a resolved element of the program. The kind of
- * elements that need an [ElementTypeRepresentation] are:
+ * elements that need an [ElementTypeInformation] are:
  *
  * - Functions (including getters and setters)
  * - Constructors (factory or generative)
  * - Fields
  * - Parameters
  * - Local variables mutated in closures
  *
  * The [ElementTypeInformation] of a function and a constructor is its
  * return type.
  *
@@ skipping 714 matching lines @@
   T visitPhiElementTypeInformation(PhiElementTypeInformation info);
   T visitElementInContainerTypeInformation(
       ElementInContainerTypeInformation info);
   T visitContainerTypeInformation(ContainerTypeInformation info);
   T visitConcreteTypeInformation(ConcreteTypeInformation info);
   T visitClosureCallSiteTypeInformation(ClosureCallSiteTypeInformation info);
   T visitStaticCallSiteTypeInformation(StaticCallSiteTypeInformation info);
   T visitDynamicCallSiteTypeInformation(DynamicCallSiteTypeInformation info);
   T visitElementTypeInformation(ElementTypeInformation info);
 }