Add named arguments support into constant ASTs.

pkg/analyzer/lib/src/summary/summarize_const_expr.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 serialization.summarize_const_expr;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/summary/format.dart';
 
@@ skipping 170 matching lines @@
     } else if (operator == TokenType.PERCENT) {
       operations.add(UnlinkedConstOperation.modulo);
     } else {
       throw new _ConstExprSerializationError('Unknown operator: $operator');
     }
   }
 
   void _serializeInstanceCreation(InstanceCreationExpression expr) {
     ConstructorName constructor = expr.constructorName;
     List<Expression> arguments = expr.argumentList.arguments;
-    arguments.forEach(serialize);
+    // Serialize the arguments.
+    List<String> argumentNames = <String>[];
+    arguments.forEach((arg) {
+      if (arg is NamedExpression) {
+        argumentNames.add(arg.name.label.name);
+        serialize(arg.expression);
+      } else {
+        serialize(arg);
+      }
+    });
+    // Add the op-code and numbers of named and positional arguments.
     operations.add(UnlinkedConstOperation.invokeConstructor);
+    ints.add(argumentNames.length);
+    strings.addAll(argumentNames);
+    ints.add(arguments.length - argumentNames.length);
+    // Serialize the reference.
     references.add(serializeType(constructor.type));
     if (constructor.name != null) {
       strings.add(constructor.name.name);
     } else {
       strings.add('');
     }
-    // TODO(scheglov) named arguments?
-    ints.add(arguments.length);
   }
 
   void _serializeListLiteral(ListLiteral expr) {
     List<Expression> elements = expr.elements;
     elements.forEach(serialize);
     TypeName typeArgument;
     if (expr.typeArguments != null &&
         expr.typeArguments.arguments.length == 1) {
       typeArgument = expr.typeArguments.arguments[0];
     }
@@ skipping 67 matching lines @@
  * Error that describes a problem during a constant expression serialization.
  */
 class _ConstExprSerializationError {
   final String message;
 
   _ConstExprSerializationError(this.message);
 
   @override
   String toString() => message;
 }