Split up TypeInferrer class.

pkg/front_end/lib/src/fasta/source/source_class_builder.dart

 // Copyright (c) 2016, 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.
 
 library fasta.source_class_builder;
 
 import 'package:front_end/src/fasta/builder/class_builder.dart'
     show ClassBuilder;
 
-import 'package:front_end/src/fasta/type_inference/type_inferrer.dart'
-    show TypeInferrer;
+import 'package:front_end/src/fasta/type_inference/type_inference_engine.dart'
+    show TypeInferenceEngine;
 
 import 'package:kernel/ast.dart'
     show Class, Constructor, Supertype, TreeNode, setParents;
 
 import '../errors.dart' show internalError;
 
 import '../kernel/kernel_builder.dart'
     show
         Builder,
         ConstructorReferenceBuilder,
@@ skipping 126 matching lines @@
   void addSyntheticConstructor(Constructor constructor) {
     String name = constructor.name.name;
     cls.constructors.add(constructor);
     constructor.parent = cls;
     DillMemberBuilder memberBuilder = new DillMemberBuilder(constructor, this);
     memberBuilder.next = constructorScopeBuilder[name];
     constructorScopeBuilder.addMember(name, memberBuilder);
   }
 
   @override
-  void prepareInitializerInference(TypeInferrer typeInferrer,
+  void prepareInitializerInference(TypeInferenceEngine typeInferenceEngine,
       LibraryBuilder library, ClassBuilder currentClass) {
     scope.forEach((name, builder) {
-      builder.prepareInitializerInference(typeInferrer, library, this);
+      builder.prepareInitializerInference(typeInferenceEngine, library, this);
     });
   }
 }