Merge the 3 different closure nodes into a single node.

runtime/vm/ast.h

Index: runtime/vm/ast.h
===================================================================
--- runtime/vm/ast.h	(revision 482)
+++ runtime/vm/ast.h	(working copy)
@@ -38,8 +38,6 @@
   V(ArgumentListNode, "args")                                                  \
   V(ArrayNode, "array")                                                        \
   V(ClosureNode, "closure")                                                    \
-  V(ImplicitInstanceClosureNode, "implicit instance closure")                  \
-  V(ImplicitStaticClosureNode, "implicit static closure")                      \
   V(InstanceCallNode, "instance call")                                         \
   V(StaticCallNode, "static call")                                             \
   V(ClosureCallNode, "closure call")                                           \
@@ -363,75 +361,41 @@
 
 class ClosureNode : public AstNode {
  public:
-  ClosureNode(intptr_t token_index, const Function& function, LocalScope* scope)
-      : AstNode(token_index), function_(function), scope_(scope) {
+  ClosureNode(intptr_t token_index,
+              const Function& function,
+              AstNode* receiver,  // Non-null for implicit instance closures.
+              LocalScope* scope)  // Null for implicit closures.
+      : AstNode(token_index),
+        function_(function),
+        receiver_(receiver),
+        scope_(scope) {
     ASSERT(function.IsZoneHandle());
-    ASSERT(function.IsNonImplicitClosureFunction());
-    ASSERT(scope_ != NULL);
+    ASSERT((function.IsNonImplicitClosureFunction() &&
+            (receiver_ == NULL) && (scope_ != NULL)) ||
+           (function.IsImplicitInstanceClosureFunction() &&
+            (receiver_ != NULL) && (scope_ == NULL)) ||
+           (function.IsImplicitStaticClosureFunction() &&
+            (receiver_ == NULL) && (scope_ == NULL)));
   }
 
   const Function& function() const { return function_; }
+  AstNode* receiver() const { return receiver_; }
   LocalScope* scope() const { return scope_; }
 
-  virtual void VisitChildren(AstNodeVisitor* visitor) const { }
-
-  DECLARE_COMMON_NODE_FUNCTIONS(ClosureNode);
-
- private:
-  const Function& function_;
-  LocalScope* scope_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ClosureNode);
-};
-
-
-class ImplicitStaticClosureNode : public AstNode {
- public:
-  ImplicitStaticClosureNode(intptr_t token_index, const Function& function)
-      : AstNode(token_index), function_(function) {
-    ASSERT(function.IsZoneHandle());
-    ASSERT(function.IsImplicitStaticClosureFunction());
-  }
-
-  const Function& function() const { return function_; }
-
-  virtual void VisitChildren(AstNodeVisitor* visitor) const { }
-
-  DECLARE_COMMON_NODE_FUNCTIONS(ImplicitStaticClosureNode);
-
- private:
-  const Function& function_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ImplicitStaticClosureNode);
-};
-
-
-class ImplicitInstanceClosureNode : public AstNode {
- public:
-  ImplicitInstanceClosureNode(intptr_t token_index,
-                             const Function& function,
-                             AstNode* receiver)
-      : AstNode(token_index), function_(function), receiver_(receiver) {
-    ASSERT(function.IsZoneHandle());
-    ASSERT(function.IsImplicitInstanceClosureFunction());
-  }
-
-  const Function& function() const { return function_; }
-  AstNode* receiver() const { return receiver_; }
-
   virtual void VisitChildren(AstNodeVisitor* visitor) const {
     if (receiver() != NULL) {
       receiver()->Visit(visitor);
     }
   }
 
-  DECLARE_COMMON_NODE_FUNCTIONS(ImplicitInstanceClosureNode);
+  DECLARE_COMMON_NODE_FUNCTIONS(ClosureNode);
 
  private:
   const Function& function_;
   AstNode* receiver_;
+  LocalScope* scope_;
 
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ImplicitInstanceClosureNode);
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ClosureNode);
 };