Add begin events for const and new expressions.

pkg/analyzer/lib/src/summary/fasta/summary_builder.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.
 
 /// Logic to build unlinked summaries.
 library summary.src.summary_builder;
 
 import 'package:front_end/src/fasta/parser/class_member_parser.dart';
 import 'package:front_end/src/fasta/parser/identifier_context.dart';
 import 'package:front_end/src/fasta/parser/parser.dart';
@@ skipping 118 matching lines @@
   }
 
   void handleNamedArgument(colon) {
     debugEvent("NamedArg");
     if (ignore) return;
     var value = pop();
     Ref name = pop();
     push(new NamedArg(name.name, value));
   }
 
-  void handleNewExpression(Token token) {
+  void endNewExpression(Token token) {
     debugEvent("NewExpression");
     if (ignore) return;
     pop(); // args
     pop(); // ctor
     push(new Invalid(hint: "new"));
   }
 
   void handleNoConstructorReferenceContinuationAfterTypeArguments(Token token) {
     debugEvent("NoConstructorReferenceContinuationAfterTypeArguments");
   }
@@ skipping 248 matching lines @@
 
   void handleConditionalExpression(Token question, Token colon) {
     debugEvent("ConditionalExpression");
     if (ignore) return;
     var falseBranch = pop();
     var trueBranch = pop();
     var cond = pop();
     push(new Conditional(cond, trueBranch, falseBranch));
   }
 
-  void handleConstExpression(Token token) {
+  @override
+  void endConstExpression(Token token) {
     debugEvent("ConstExpression");
     if (ignore) return;
     List args = pop();
     var constructorName = pop();
     var positional = args.where((a) => a is! NamedArg).toList();
     var named = args.where((a) => a is NamedArg).toList();
     push(new ConstCreation(constructorName, positional, named));
   }
 
   void handleIdentifier(Token token, IdentifierContext context) {
@@ skipping 240 matching lines @@
   }
 
   void handleNamedArgument(colon) {
     debugEvent("NamedArg");
     if (ignore) return;
     pop();
     pop();
     push(NullValue.Arguments);
   }
 
-  void handleNewExpression(Token token) {
+  void endNewExpression(Token token) {
     debugEvent("NewExpression");
     if (ignore) return;
     pop(); // args
     /* var ctor = */ pop(); // ctor
     throw new UnimplementedError(); // TODO(paulberry): fix the code below.
     // push(new Opaque(type: ctor.type, hint: "new"));
   }
 
   void handleNoConstructorReferenceContinuationAfterTypeArguments(Token token) {
     debugEvent("NoConstructorReferenceContinuationAfterTypeArguments");
@@ skipping 870 matching lines @@
 }
 
 /// Internal representation of an initialized name.
 class _InitializedName {
   final String name;
   final UnlinkedExecutableBuilder initializer;
   _InitializedName(this.name, this.initializer);
 
   toString() => "II:" + (initializer != null ? "$name = $initializer" : name);
 }