Implement yield* (delegating yield)

src/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1964 matching lines @@
     SUSPEND,     // A normal yield: { value: EXPRESSION, done: false }
     DELEGATING,  // A yield*.
     FINAL        // A return: { value: EXPRESSION, done: true }
   };
 
   Expression* generator_object() const { return generator_object_; }
   Expression* expression() const { return expression_; }
   Kind yield_kind() const { return yield_kind_; }
   virtual int position() const { return pos_; }
 
+  // Delegating yield surrounds the "yield" in a "try/catch".  This index
+  // locates the catch handler in the handler table, and is equivalent to
+  // TryCatchStatement::index().
+  int index() const {
+    ASSERT(yield_kind() == DELEGATING);
+    return index_;
+  }
+  void set_index(int index) {
+    ASSERT(yield_kind() == DELEGATING);
+    index_ = index;
+  }
+
  protected:
   Yield(Isolate* isolate,
         Expression* generator_object,
         Expression* expression,
         Kind yield_kind,
         int pos)
       : Expression(isolate),
         generator_object_(generator_object),
         expression_(expression),
         yield_kind_(yield_kind),
+        index_(-1),
         pos_(pos) { }
 
  private:
   Expression* generator_object_;
   Expression* expression_;
   Kind yield_kind_;
+  int index_;
   int pos_;
 };
 
 
 class Throw: public Expression {
  public:
   DECLARE_NODE_TYPE(Throw)
 
   Expression* exception() const { return exception_; }
   virtual int position() const { return pos_; }
@@ skipping 1027 matching lines @@
  private:
   Isolate* isolate_;
   Zone* zone_;
   Visitor visitor_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_