Implement symbol @@hasInstance for ES6 instanceof support.

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index 2b89c4c66da5d15ee82d263e585e14c1449b8301..6294b26d6ccaaf3cddd24b52863524cfa54d3401 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -3483,6 +3483,45 @@ BUILTIN(GeneratorFunctionConstructor) {
   return *result;
 }
 
+// ES6 section 19.2.3.6 Function.prototype[@@hasInstance](V)
+BUILTIN(FunctionHasInstance) {
+  HandleScope scope(isolate);
+  Handle<Object> callable = args.receiver();
+  Handle<Object> object = args.atOrUndefined(isolate, 1);
+
+  // {callable} must have a [[Call]] internal method.
+  if (!callable->IsCallable()) {
+    return isolate->heap()->false_value();
+  }
+  // If {object} is not a receiver, return false.
+  if (!object->IsJSReceiver()) {
+    return isolate->heap()->false_value();
+  }
+  // Check if {callable} is bound, if so, get [[BoundTargetFunction]] from it
+  // and use that instead of {callable}.
+  while (callable->IsJSBoundFunction()) {
+    callable =
+        handle(Handle<JSBoundFunction>::cast(callable)->bound_target_function(),
+               isolate);
+  }
+  DCHECK(callable->IsCallable());
+  // Get the "prototype" of {callable}; raise an error if it's not a receiver.
+  Handle<Object> prototype;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, prototype,
+      Object::GetProperty(callable, isolate->factory()->prototype_string()));
+  if (!prototype->IsJSReceiver()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate,
+        NewTypeError(MessageTemplate::kInstanceofNonobjectProto, prototype));
+  }
+  // Return whether or not {prototype} is in the prototype chain of {object}.
+  Handle<JSReceiver> receiver = Handle<JSReceiver>::cast(object);
+  Maybe<bool> result =
+      JSReceiver::HasInPrototypeChain(isolate, receiver, prototype);
+  MAYBE_RETURN(result, isolate->heap()->exception());
+  return isolate->heap()->ToBoolean(result.FromJust());
+}
 
 // ES6 section 19.4.1.1 Symbol ( [ description ] ) for the [[Call]] case.
 BUILTIN(SymbolConstructor) {