Introduce IsUndefined(Isolate*) and IsTheHole(Isolate*)

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 3cd0553d58e1cfe90604e1cf45f1213c4e9ccd75..6b350b26a456b7988c6cc94eb36c95d89e79e034 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1064,6 +1064,9 @@ class Object {
   STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
 #undef DECLARE_STRUCT_PREDICATE
 
+  INLINE(bool IsTheHole(Isolate* isolate) const);
+  INLINE(bool IsUndefined(Isolate* isolate) const);
+
   // ES6, section 7.2.2 IsArray.  NOT to be confused with %_IsArray.
   MUST_USE_RESULT static Maybe<bool> IsArray(Handle<Object> object);
 
@@ -1560,6 +1563,9 @@ class HeapObject: public Object {
   STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
 #undef DECLARE_STRUCT_PREDICATE
 
+  INLINE(bool IsTheHole(Isolate* isolate) const);
+  INLINE(bool IsUndefined(Isolate* isolate) const);
+
   // Converts an address to a HeapObject pointer.
   static inline HeapObject* FromAddress(Address address) {
     DCHECK_TAG_ALIGNED(address);