[generators] Implement Generator.prototype.return.

src/objects.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 7253 matching lines @@
   // Layout description.
   static const int kFunctionOffset = JSObject::kHeaderSize;
   static const int kContextOffset = kFunctionOffset + kPointerSize;
   static const int kReceiverOffset = kContextOffset + kPointerSize;
   static const int kInputOffset = kReceiverOffset + kPointerSize;
   static const int kContinuationOffset = kInputOffset + kPointerSize;
   static const int kOperandStackOffset = kContinuationOffset + kPointerSize;
   static const int kSize = kOperandStackOffset + kPointerSize;
 
   // Resume mode, for use by runtime functions.
-  enum ResumeMode { NEXT, THROW };
+  enum ResumeMode { NEXT, RETURN, THROW };
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject);
 };
 
 
 // Representation for module instance objects.
 class JSModule: public JSObject {
  public:
   // [context]: the context holding the module's locals, or undefined if none.
@@ skipping 3537 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_