Implement Fast Accessor Builder

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 97ba34d496a1741c7ba0d986547d06bc494ebfc0..b2198f7f2f6eb07bce2af89d16f7212f4c9b3201 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -136,6 +136,10 @@ class CallHandlerHelper;
 class EscapableHandleScope;
 template<typename T> class ReturnValue;
 
+namespace experimental {
+class FastAccessorBuilder;
+}  // namespace experimental
+
 namespace internal {
 class Arguments;
 class Heap;
@@ -4417,6 +4421,16 @@ class V8_EXPORT FunctionTemplate : public Template {
    * the callback cannot be null.
    */
   static Local<FunctionTemplate> NewWithFastHandler(
+      Isolate* isolate, FunctionCallback callback,
+      experimental::FastAccessorBuilder* fast_handler = nullptr,
+      Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0);
+
+  /**
+   * Creates a function template with a fast handler. If a fast handler is set,
+   * the callback cannot be null.
+   */
+  static Local<FunctionTemplate> NewWithFastHandler(
       Isolate* isolate, FunctionCallback callback, Local<Value> fast_handler,
       Local<Value> data = Local<Value>(),
       Local<Signature> signature = Local<Signature>(), int length = 0);
@@ -4431,9 +4445,9 @@ class V8_EXPORT FunctionTemplate : public Template {
    * callback is called whenever the function created from this
    * FunctionTemplate is called.
    */
-  void SetCallHandler(FunctionCallback callback,
-                      Local<Value> data = Local<Value>(),
-                      Local<Value> fast_handler = Local<Value>());
+  void SetCallHandler(
+      FunctionCallback callback, Local<Value> data = Local<Value>(),
+      experimental::FastAccessorBuilder* fast_handler = nullptr);
 
   /** Set the predefined length property for the FunctionTemplate. */
   void SetLength(int length);