Make generators non-constructable.

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 5527 matching lines @@
   // Tells whether the object in the prototype property will be used
   // for instances created from this function.  If the prototype
   // property is set to a value that is not a JSObject, the prototype
   // property will not be used to create instances of the function.
   // See ECMA-262, 13.2.2.
   inline void set_non_instance_prototype(bool value);
   inline bool has_non_instance_prototype();
 
   // Tells whether the instance has a [[Construct]] internal method.
   // This property is implemented according to ES6, section 7.2.4.
-  inline void set_is_constructor();
+  inline void set_is_constructor(bool value);
   inline bool is_constructor() const;
 
   // Tells whether the instance with this map should be ignored by the
   // Object.getPrototypeOf() function and the __proto__ accessor.
   inline void set_is_hidden_prototype();
   inline bool is_hidden_prototype() const;
 
   // Records and queries whether the instance has a named interceptor.
   inline void set_has_named_interceptor();
   inline bool has_named_interceptor();
@@ skipping 5185 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_