Use instance type in Object.prototype.toString().

src/objects.h

 // Copyright 2015 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_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/assert-scope.h"
@@ skipping 397 matching lines @@
   V(FIXED_DOUBLE_ARRAY_TYPE)                                    \
   V(SHARED_FUNCTION_INFO_TYPE)                                  \
   V(WEAK_CELL_TYPE)                                             \
   V(TRANSITION_ARRAY_TYPE)                                      \
                                                                 \
   V(JS_MESSAGE_OBJECT_TYPE)                                     \
                                                                 \
   V(JS_VALUE_TYPE)                                              \
   V(JS_DATE_TYPE)                                               \
   V(JS_OBJECT_TYPE)                                             \
+  V(JS_ARGUMENTS_TYPE)                                          \
   V(JS_CONTEXT_EXTENSION_OBJECT_TYPE)                           \
   V(JS_GENERATOR_OBJECT_TYPE)                                   \
   V(JS_MODULE_TYPE)                                             \
   V(JS_GLOBAL_OBJECT_TYPE)                                      \
   V(JS_GLOBAL_PROXY_TYPE)                                       \
   V(JS_API_OBJECT_TYPE)                                         \
   V(JS_SPECIAL_API_OBJECT_TYPE)                                 \
   V(JS_ARRAY_TYPE)                                              \
   V(JS_ARRAY_BUFFER_TYPE)                                       \
   V(JS_TYPED_ARRAY_TYPE)                                        \
   V(JS_DATA_VIEW_TYPE)                                          \
   V(JS_PROXY_TYPE)                                              \
   V(JS_SET_TYPE)                                                \
   V(JS_MAP_TYPE)                                                \
   V(JS_SET_ITERATOR_TYPE)                                       \
   V(JS_MAP_ITERATOR_TYPE)                                       \
   V(JS_WEAK_MAP_TYPE)                                           \
   V(JS_WEAK_SET_TYPE)                                           \
   V(JS_PROMISE_TYPE)                                            \
   V(JS_REGEXP_TYPE)                                             \
+  V(JS_ERROR_TYPE)                                              \
                                                                 \
   V(JS_BOUND_FUNCTION_TYPE)                                     \
   V(JS_FUNCTION_TYPE)                                           \
   V(DEBUG_INFO_TYPE)                                            \
   V(BREAK_POINT_INFO_TYPE)
 
 // Since string types are not consecutive, this macro is used to
 // iterate over them.
 #define STRING_TYPE_LIST(V)                                                   \
   V(STRING_TYPE, kVariableSizeSentinel, string, String)                       \
@@ skipping 257 matching lines @@
   JS_GLOBAL_PROXY_TYPE,
   // Like JS_API_OBJECT_TYPE, but requires access checks and/or has
   // interceptors.
   JS_SPECIAL_API_OBJECT_TYPE,  // LAST_SPECIAL_RECEIVER_TYPE
   JS_VALUE_TYPE,               // LAST_CUSTOM_ELEMENTS_RECEIVER
   JS_MESSAGE_OBJECT_TYPE,
   JS_DATE_TYPE,
   // Like JS_OBJECT_TYPE, but created from API function.
   JS_API_OBJECT_TYPE,
   JS_OBJECT_TYPE,
+  JS_ARGUMENTS_TYPE,
   JS_CONTEXT_EXTENSION_OBJECT_TYPE,
   JS_GENERATOR_OBJECT_TYPE,
   JS_MODULE_TYPE,
   JS_ARRAY_TYPE,
   JS_ARRAY_BUFFER_TYPE,
   JS_TYPED_ARRAY_TYPE,
   JS_DATA_VIEW_TYPE,
   JS_SET_TYPE,
   JS_MAP_TYPE,
   JS_SET_ITERATOR_TYPE,
   JS_MAP_ITERATOR_TYPE,
   JS_WEAK_MAP_TYPE,
   JS_WEAK_SET_TYPE,
   JS_PROMISE_TYPE,
   JS_REGEXP_TYPE,
+  JS_ERROR_TYPE,
   JS_BOUND_FUNCTION_TYPE,
   JS_FUNCTION_TYPE,  // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE
 
   // Pseudo-types
   FIRST_TYPE = 0x0,
   LAST_TYPE = JS_FUNCTION_TYPE,
   FIRST_NAME_TYPE = FIRST_TYPE,
   LAST_NAME_TYPE = SYMBOL_TYPE,
   FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE,
   LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE,
@@ skipping 1192 matching lines @@
 
   // ES6 [[PreventExtensions]] (when passed DONT_THROW)
   MUST_USE_RESULT static Maybe<bool> PreventExtensions(
       Handle<JSReceiver> object, ShouldThrow should_throw);
 
   MUST_USE_RESULT static Maybe<bool> IsExtensible(Handle<JSReceiver> object);
 
   // Returns the class name ([[Class]] property in the specification).
   String* class_name();
 
-  // Returns the builtin string tag used in Object.prototype.toString.
-  MUST_USE_RESULT static MaybeHandle<String> BuiltinStringTag(
-      Handle<JSReceiver> object);
-
   // Returns the constructor name (the name (possibly, inferred name) of the
   // function that was used to instantiate the object).
   static Handle<String> GetConstructorName(Handle<JSReceiver> receiver);
 
   Context* GetCreationContext();
 
   MUST_USE_RESULT static inline Maybe<PropertyAttributes> GetPropertyAttributes(
       Handle<JSReceiver> object, Handle<Name> name);
   MUST_USE_RESULT static inline Maybe<PropertyAttributes>
   GetOwnPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
@@ skipping 8859 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_