Add Object::IsNullOrUndefined(Isolate*) helper method

src/builtins/builtins-utils.h

 // Copyright 2016 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_BUILTINS_BUILTINS_UTILS_H_
 #define V8_BUILTINS_BUILTINS_UTILS_H_
 
 #include "src/arguments.h"
 #include "src/base/logging.h"
 #include "src/builtins/builtins.h"
@@ skipping 127 matching lines @@
         NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,          \
                      isolate->factory()->NewStringFromAsciiChecked(method), \
                      args.receiver()));                                     \
   }                                                                         \
   Handle<Type> name = Handle<Type>::cast(args.receiver())
 
 // Throws a TypeError for {method} if the receiver is not coercible to Object,
 // or converts the receiver to a String otherwise and assigns it to a new var
 // with the given {name}.
 #define TO_THIS_STRING(name, method)                                          \
-  if (args.receiver()->IsNull(isolate) ||                                     \
-      args.receiver()->IsUndefined(isolate)) {                                \
+  if (args.receiver()->IsNullOrUndefined(isolate)) {                          \
     THROW_NEW_ERROR_RETURN_FAILURE(                                           \
         isolate,                                                              \
         NewTypeError(MessageTemplate::kCalledOnNullOrUndefined,               \
                      isolate->factory()->NewStringFromAsciiChecked(method))); \
   }                                                                           \
   Handle<String> name;                                                        \
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(                                         \
       isolate, name, Object::ToString(isolate, args.receiver()))
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_BUILTINS_BUILTINS_UTILS_H_