Add begin events for const and new expressions.

pkg/analyzer/lib/src/fasta/ast_builder.dart

Index: pkg/analyzer/lib/src/fasta/ast_builder.dart
diff --git a/pkg/analyzer/lib/src/fasta/ast_builder.dart b/pkg/analyzer/lib/src/fasta/ast_builder.dart
index 8c897c5c8b039e923ff3fc947af4cf9746573196..a5f887c69c5c8c02c802456e131d6c8a5ab6510f 100644
--- a/pkg/analyzer/lib/src/fasta/ast_builder.dart
+++ b/pkg/analyzer/lib/src/fasta/ast_builder.dart
@@ -82,7 +82,7 @@ class AstBuilder extends ScopeListener {
   }
 
   @override
-  void handleConstExpression(Token token) {
+  void endConstExpression(Token token) {
     debugEvent("ConstExpression");
     _handleInstanceCreation(token);
   }
@@ -95,7 +95,7 @@ class AstBuilder extends ScopeListener {
   }
 
   @override
-  void handleNewExpression(Token token) {
+  void endNewExpression(Token token) {
     debugEvent("NewExpression");
     _handleInstanceCreation(token);
   }