Perform type inference on constructor field initializer expressions.

pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.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.
 
 /// This file declares a "shadow hierarchy" of concrete classes which extend
 /// the kernel class hierarchy, adding methods and fields needed by the
 /// BodyBuilder.
 ///
 /// Instances of these classes may be created using the factory methods in
 /// `ast_factory.dart`.
@@ skipping 672 matching lines @@
 
   @override
   void setInferredType(
       TypeInferenceEngineImpl engine, String uri, DartType inferredType) {
     engine.instrumentation?.record(Uri.parse(uri), fileOffset, 'topType',
         new InstrumentationValueForType(inferredType));
     type = inferredType;
   }
 }
 
+/// Concrete shadow object representing a field initializer in kernel form.
+class KernelFieldInitializer extends FieldInitializer
+    implements KernelInitializer {
+  KernelFieldInitializer(Field field, Expression value) : super(field, value);
+
+  @override
+  void _inferInitializer(KernelTypeInferrer inferrer) {
+    inferrer.listener.fieldInitializerEnter(this);
+    inferrer.inferExpression(value, field.type, false);
+    inferrer.listener.fieldInitializerExit(this);
+  }
+}
+
 /// Concrete shadow object representing a for-in loop in kernel form.
 class KernelForInStatement extends ForInStatement implements KernelStatement {
   final bool _declaresVariable;
 
   KernelForInStatement(VariableDeclaration variable, Expression iterable,
       Statement body, this._declaresVariable,
       {bool isAsync: false})
       : super(variable, iterable, body, isAsync: isAsync);
 
   @override
@@ skipping 1712 matching lines @@
   accept(v) => unsupported("accept", -1, null);
 
   accept1(v, arg) => unsupported("accept1", -1, null);
 
   getStaticType(types) => unsupported("getStaticType", -1, null);
 
   transformChildren(v) => unsupported("transformChildren", -1, null);
 
   visitChildren(v) => unsupported("visitChildren", -1, null);
 }