Add support for the new function-type syntax.

pkg/compiler/lib/src/resolution/signatures.dart

 // Copyright (c) 2014, 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 dart2js.resolution.signatures;
 
 import '../common.dart';
 import '../common/resolution.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart';
@@ skipping 284 matching lines @@
    */
   static FunctionSignature analyze(
       Resolution resolution,
       Scope scope,
       NodeList typeVariables,
       NodeList formalParameters,
       Node returnNode,
       FunctionTypedElement element,
       ResolutionRegistry registry,
       {MessageKind defaultValuesError,
+      bool isNewSyntax: false,

[Siggi Cherem (dart-lang), 2016/12/12 23:20:40]

while you are here, would you mind updating the dartdoc above. I would had
assumed that this was only used for function expressions and not for typedefs.

       bool createRealParameters: false,
       bool isFunctionExpression: false}) {
     DiagnosticReporter reporter = resolution.reporter;
 
     List<DartType> createTypeVariables(NodeList typeVariableNodes) {
       if (element.isPatch) {
         FunctionTypedElement origin = element.origin;
         origin.computeType(resolution);
         return origin.typeVariables;
       }
@@ skipping 96 matching lines @@
     LinkBuilder<DartType> parameterTypes = new LinkBuilder<DartType>();
     for (FormalElement parameter in parameters) {
       parameterTypes.addLast(parameter.type);
     }
     List<DartType> optionalParameterTypes = const <DartType>[];
     List<String> namedParameters = const <String>[];
     List<DartType> namedParameterTypes = const <DartType>[];
     List<Element> orderedOptionalParameters =
         visitor.optionalParameters.toList();
     if (visitor.optionalParametersAreNamed) {
-      // TODO(karlklose); replace when [visitor.optinalParameters] is a [List].
+      // TODO(karlklose); replace when [visitor.optionalParameters] is a [List].
       orderedOptionalParameters.sort((Element a, Element b) {
         return a.name.compareTo(b.name);
       });
       LinkBuilder<String> namedParametersBuilder = new LinkBuilder<String>();
       LinkBuilder<DartType> namedParameterTypesBuilder =
           new LinkBuilder<DartType>();
       for (FormalElement parameter in orderedOptionalParameters) {
         namedParametersBuilder.addLast(parameter.name);
         namedParameterTypesBuilder.addLast(parameter.type);
       }
@@ skipping 50 matching lines @@
 /// variables of the function signature itself when its signature is analyzed.
 class FunctionSignatureBuildingScope extends TypeVariablesScope {
   @override
   final List<DartType> typeVariables;
 
   FunctionSignatureBuildingScope(Scope parent, this.typeVariables)
       : super(parent);
 
   String toString() => 'FunctionSignatureBuildingScope($typeVariables)';
 }