Remove support for 'argument definitions test' from dart2js.

sdk/lib/_internal/compiler/implementation/scanner/listener.dart

Index: sdk/lib/_internal/compiler/implementation/scanner/listener.dart
diff --git a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
index 17f790c4ce784f10154672bef99e3b74e405257a..5c69c0828fa5e5b5cbbd291fc165070f7180d5c4 100644
--- a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
+++ b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
@@ -11,12 +11,6 @@ const bool VERBOSE = false;
  * on parser errors.
  */
 class Listener {
-  void beginArgumentDefinitionTest(Token token) {
-  }
-
-  void endArgumentDefinitionTest(Token beginToken, Token endToken) {
-  }
-
   void beginArguments(Token token) {
   }
 
@@ -1174,10 +1168,6 @@ class NodeListener extends ElementListener {
     pushNode(tag);
   }
 
-  void endArgumentDefinitionTest(Token beginToken, Token endToken) {
-    pushNode(new Send.prefix(popNode(), new Operator(beginToken)));
-  }
-
   void endClassDeclaration(int interfacesCount, Token beginToken,
                            Token extendsKeyword, Token implementsKeyword,
                            Token endToken) {