Adds support for remaining generic method syntax constructs.

pkg/compiler/lib/src/parser/element_listener.dart

Index: pkg/compiler/lib/src/parser/element_listener.dart
diff --git a/pkg/compiler/lib/src/parser/element_listener.dart b/pkg/compiler/lib/src/parser/element_listener.dart
index b089ae5202aba3eab0f8abd37221ab3f4d2abaf6..1a2b710ea07590c716ef1bf27b3c83121bbea8e2 100644
--- a/pkg/compiler/lib/src/parser/element_listener.dart
+++ b/pkg/compiler/lib/src/parser/element_listener.dart
@@ -368,8 +368,17 @@ class ElementListener extends Listener {
     pushNode(null);
   }
 
+  void handleNoExtendsNorSuper(Token token) {
+    pushNode(null);
+  }
+
+  void handleExtendsOrSuper(Token token) {
+    pushNode(null); // Supporting only syntax, we do not need to distinguish.
+  }
+
   void endTypeVariable(Token token) {
     TypeAnnotation bound = popNode();
+    popNode(); // `extends` or `super`
     Identifier name = popNode();
     pushNode(new TypeVariable(name, bound));
     rejectBuiltInIdentifier(name);