fix #26414, infer return types of local functions

pkg/analyzer/test/src/summary/resynthesize_ast_test.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 analyzer.test.src.summary.resynthesize_ast_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/generated/engine.dart'
@@ skipping 549 matching lines @@
   }
 
   @override
   @failingTest
   void test_inferenceInCyclesIsDeterministic() {
     super.test_inferenceInCyclesIsDeterministic();
   }
 
   @override
   @failingTest
+  void test_inferLocalFunctionReturnType() {
+    super.test_inferLocalFunctionReturnType();
+  }
+
+  @override
+  @failingTest
   void test_inferredType_opAssignToProperty_prefixedIdentifier() {
     super.test_inferredType_opAssignToProperty_prefixedIdentifier();
   }
 
   @override
   @failingTest
   void test_inferredType_opAssignToProperty_prefixedIdentifier_viaInterface() {
     super
         .test_inferredType_opAssignToProperty_prefixedIdentifier_viaInterface();
   }
@@ skipping 238 matching lines @@
     }
 
     UnlinkedUnit definingUnit = _getUnlinkedUnit(librarySource);
     LinkedLibraryBuilder linkedLibrary =
         prelink(definingUnit, getPart, getImport);
     linkedLibrary.dependencies.skip(1).forEach((LinkedDependency d) {
       _serializeLibrary(resolveRelativeUri(d.uri));
     });
   }
 }