Adds the possibility of setting a Code object as the callback of a FunctionTemplate.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 53db6ea6a0401a26a5a6817ecda3e2f18ac600cf..61dd3a6a915092f4061ecd9964eb2e40b1e0a43a 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -4411,6 +4411,15 @@ class V8_EXPORT FunctionTemplate : public Template {
       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);
+
   /** Returns the unique function instance in the current execution context.*/
   V8_DEPRECATE_SOON("Use maybe version", Local<Function> GetFunction());
   V8_WARN_UNUSED_RESULT MaybeLocal<Function> GetFunction(
@@ -4422,7 +4431,8 @@ class V8_EXPORT FunctionTemplate : public Template {
    * FunctionTemplate is called.
    */
   void SetCallHandler(FunctionCallback callback,
-                      Local<Value> data = Local<Value>());
+                      Local<Value> data = Local<Value>(),
+                      Local<Value> fast_handler = Local<Value>());
 
   /** Set the predefined length property for the FunctionTemplate. */
   void SetLength(int length);