It's alive (first kernel inference test)

pkg/compiler/lib/src/inferrer/kernel_inferrer_engine.dart

 // Copyright (c) 2017, 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.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../closure.dart';
 import '../common.dart';
 import '../common_elements.dart';
 import '../compiler.dart';
@@ skipping 79 matching lines @@
       ClosedWorldRefiner closedWorldRefiner,
       FunctionEntity mainElement)
       : super(
             compiler,
             closedWorld,
             closedWorldRefiner,
             mainElement,
             new KernelTypeSystemStrategy(
                 _elementMap, _globalLocalsMap, _closureDataLookup));
 
+  ElementEnvironment get _elementEnvironment => _elementMap.elementEnvironment;
+
   @override
   ConstantValue getFieldConstant(FieldEntity field) {
-    throw new UnimplementedError('KernelInferrerEngine.getFieldConstant');
+    return _elementMap.getFieldConstantValue(field);
   }
 
   @override
   bool isFieldInitializerPotentiallyNull(
       FieldEntity field, ir.Node initializer) {
-    throw new UnimplementedError(
-        'KernelInferrerEngine.isFieldInitializerPotentiallyNull');
+    // TODO(johnniwinther): Implement the ad-hoc check in ast inferrer?
+    return true;
   }
 
   @override
   TypeInformation computeMemberTypeInformation(
       MemberEntity member, ir.Node body) {
     KernelTypeGraphBuilder visitor =
-        new KernelTypeGraphBuilder(member, compiler, _elementMap, this);
+        new KernelTypeGraphBuilder(member, compiler, _elementMap, this, body);
     return visitor.run();
   }
 
   @override
   FunctionEntity lookupCallMethod(ClassEntity cls) {
     throw new UnimplementedError('KernelInferrerEngine.lookupCallMethod');
   }
 
   @override
   void forEachParameter(FunctionEntity method, void f(Local parameter)) {
@@ skipping 133 matching lines @@
       ConstructorEntity constructor = member;
       if (constructor.isFactoryConstructor) {
         DartType type = _elementEnvironment.getFunctionType(constructor);
         return new FactoryConstructorTypeInformation(constructor, type);
       } else {
         return new GenerativeConstructorTypeInformation(constructor);
       }
     }
   }
 }