[es6] Reintroduce the instanceof operator in the backends.

src/runtime/runtime-object.cc

Index: src/runtime/runtime-object.cc
diff --git a/src/runtime/runtime-object.cc b/src/runtime/runtime-object.cc
index 4b4588804f53c35aaa529e4ffe26362ce24bac84..8c9c2305f1a14201a71bd2d3e795cbb682c5f8e0 100644
--- a/src/runtime/runtime-object.cc
+++ b/src/runtime/runtime-object.cc
@@ -983,97 +983,6 @@ RUNTIME_FUNCTION(Runtime_Compare) {
   return isolate->heap()->exception();
 }
 
-
-RUNTIME_FUNCTION(Runtime_InstanceOf) {
-  // TODO(4447): Remove this function when ES6 instanceof ships for good.
-  DCHECK(!FLAG_harmony_instanceof);
-
-  // ECMA-262, section 11.8.6, page 54.
-  HandleScope shs(isolate);
-  DCHECK_EQ(2, args.length());
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, callable, 1);
-  // {callable} must have a [[Call]] internal method.
-  if (!callable->IsCallable()) {
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate,
-        NewTypeError(MessageTemplate::kInstanceofFunctionExpected, callable));
-  }
-  // 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,
-      JSReceiver::GetProperty(Handle<JSReceiver>::cast(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());
-}
-
-RUNTIME_FUNCTION(Runtime_OrdinaryHasInstance) {
-  // ES6 section 19.2.3.6 Function.prototype[@@hasInstance](V)
-  HandleScope shs(isolate);
-  DCHECK_EQ(2, args.length());
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, callable, 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,
-      JSReceiver::GetProperty(Handle<JSReceiver>::cast(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());
-}
-
-
 RUNTIME_FUNCTION(Runtime_HasInPrototypeChain) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());