Correctly handle const constructors with type parameters.

lib/compiler/implementation/scanner/listener.dart

Index: lib/compiler/implementation/scanner/listener.dart
===================================================================
--- lib/compiler/implementation/scanner/listener.dart	(revision 12600)
+++ lib/compiler/implementation/scanner/listener.dart	(working copy)
@@ -1372,12 +1372,8 @@
   }
 
   void handleConstExpression(Token token, bool named) {
-    NodeList arguments = popNode();
-    if (named) {
-      Identifier name = popNode();
-    }
-    TypeAnnotation type = popNode();
-    pushNode(new NewExpression(token, new Send(null, type, arguments)));
+    // [token] carries the 'const' information.
+    handleNewExpression(token, named);
   }
 
   void handleOperatorName(Token operatorKeyword, Token token) {