More generic function type cases working

pkg/analyzer/lib/src/generated/error_verifier.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 analyzer.src.generated.error_verifier;
 
 import 'dart:collection';
 import "dart:math" as math;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 5361 matching lines @@
    *
    * See [CompileTimeErrorCode.PRIVATE_OPTIONAL_PARAMETER].
    */
   void _checkForPrivateOptionalParameter(FormalParameter parameter) {
     // should be named parameter
     if (parameter.kind != ParameterKind.NAMED) {
       return;
     }
     // name should start with '_'
     SimpleIdentifier name = parameter.identifier;
-    if (name.isSynthetic || !StringUtilities.startsWithChar(name.name, 0x5F)) {
+    if (name == null ||
+        name.isSynthetic ||
+        !StringUtilities.startsWithChar(name.name, 0x5F)) {
       return;
     }
 
     _errorReporter.reportErrorForNode(
         CompileTimeErrorCode.PRIVATE_OPTIONAL_PARAMETER, parameter);
   }
 
   /**
    * Check whether the given constructor [declaration] is the redirecting
    * generative constructor and references itself directly or indirectly. The
@@ skipping 1764 matching lines @@
 class _InvocationCollector extends RecursiveAstVisitor {
   final List<String> superCalls = <String>[];
 
   @override
   visitMethodInvocation(MethodInvocation node) {
     if (node.target is SuperExpression) {
       superCalls.add(node.methodName.name);
     }
   }
 }