Add FunctionDeclaration node.

frog/leg/scanner/listener.dart

Index: frog/leg/scanner/listener.dart
diff --git a/frog/leg/scanner/listener.dart b/frog/leg/scanner/listener.dart
index 5461ff5023fab04b519502b54d21d59896adb912..36898d5941f56993c79abc376dae0b9e63648406 100644
--- a/frog/leg/scanner/listener.dart
+++ b/frog/leg/scanner/listener.dart
@@ -91,6 +91,12 @@ class Listener {
   void endFunction(Token getOrSet, Token endToken) {
   }
 
+  void beginFunctionDeclaration(Token token) {
+  }
+
+  void endFunctionDeclaration(Token token) {
+  }
+
   void beginFunctionBody(Token token) {
   }
 
@@ -1034,6 +1040,10 @@ class NodeListener extends ElementListener {
                                     modifiers, initializers, getOrSet));
   }
 
+  void endFunctionDeclaration(Token endToken) {
+    pushNode(new FunctionDeclaration(popNode()));
+  }
+
   void endVariablesDeclaration(int count, Token endToken) {
     // TODO(ahe): Pick one name for this concept, either
     // VariablesDeclaration or VariableDefinitions.