Add support for generic function type syntax, part 1

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/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/type.dart' show DartType;
 import 'package:analyzer/src/summary/format.dart';
@@ skipping 160 matching lines @@
    * [name] and [arguments].  It is expected that [type] corresponds to the
    * given [name] and [arguments].  The parameter [type] might be `null` if the
    * type is not resolved.
    */
   EntityRefBuilder serializeType(
       DartType type, Identifier name, TypeArgumentList arguments);
 
   /**
    * Return [EntityRefBuilder] that corresponds to the given [type].
    */
-  EntityRefBuilder serializeTypeName(TypeName type) {
-    return serializeType(type?.type, type?.name, type?.typeArguments);
+  EntityRefBuilder serializeTypeName(TypeAnnotation type) {
+    if (type is TypeName) {
+      return serializeType(type?.type, type?.name, type?.typeArguments);
+    }
+    throw new ArgumentError(
+        'Cannot serialize an instance of ${type.runtimeType}');
   }
 
   /**
    * Return the [UnlinkedExprBuilder] that corresponds to the state of this
    * serializer.
    */
   UnlinkedExprBuilder toBuilder() {
     return new UnlinkedExprBuilder(
         isValidConst: isValidConst,
         operations: operations,
@@ skipping 449 matching lines @@
       operations.add(UnlinkedExprOperation.concatenate);
       ints.add(interpolation.elements.length);
     }
   }
 
   void _serializeTypeArguments(TypeArgumentList typeArguments) {
     if (typeArguments == null) {
       ints.add(0);
     } else {
       ints.add(typeArguments.arguments.length);
-      for (TypeName typeName in typeArguments.arguments) {
-        references.add(serializeTypeName(typeName));
+      for (TypeAnnotation type in typeArguments.arguments) {
+        references.add(serializeTypeName(type));
       }
     }
   }
 }