Add AstBuilder support for enum declarations.

pkg/analyzer/test/generated/parser_fasta_test.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/generated/parser.dart' as analyzer;
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:front_end/src/fasta/analyzer/ast_builder.dart';
@@ skipping 1055 matching lines @@
 
   @override
   @failingTest
   void test_parseDirectives_script() {
     // TODO(paulberry): No objects placed on stack
     super.test_parseDirectives_script();
   }
 
   @override
   @failingTest
-  void test_parseEnumDeclaration_one() {
-    // TODO(paulberry): Unhandled event: Enum
-    super.test_parseEnumDeclaration_one();
-  }
-
-  @override
-  @failingTest
-  void test_parseEnumDeclaration_trailingComma() {
-    // TODO(paulberry): Unhandled event: Enum
-    super.test_parseEnumDeclaration_trailingComma();
-  }
-
-  @override
-  @failingTest
-  void test_parseEnumDeclaration_two() {
-    // TODO(paulberry): Unhandled event: Enum
-    super.test_parseEnumDeclaration_two();
-  }
-
-  @override
-  @failingTest
   void test_parseFunctionDeclaration_function() {
     // TODO(paulberry): handle doc comments
     super.test_parseFunctionDeclaration_function();
   }
 
   @override
   @failingTest
   void test_parseFunctionDeclaration_functionWithTypeParameters() {
     // TODO(paulberry): handle doc comments
     super.test_parseFunctionDeclaration_functionWithTypeParameters();
@@ skipping 113 matching lines @@
   void test_parseTypeAlias_genericFunction_typeParameters_voidReturnType() {
     super.test_parseTypeAlias_genericFunction_typeParameters_voidReturnType();
   }
 
   @override
   @failingTest
   void test_parseTypeAlias_genericFunction_voidReturnType() {
     super.test_parseTypeAlias_genericFunction_voidReturnType();
   }
 }