[regexp] Extract code to regexp-utils.{h,cc}

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index bbde851fb70d7dbfeeac8f1593a3433e4dfed8f8..7c44efd33c4f8e3264293008b8a06504da15fb38 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -1977,26 +1977,6 @@ Object* GetSimpleHash(Object* object) {
 
 }  // namespace
 
-Maybe<bool> Object::IsRegExp(Isolate* isolate, Handle<Object> object) {
-  if (!object->IsJSReceiver()) return Just(false);
-
-  Handle<JSReceiver> receiver = Handle<JSReceiver>::cast(object);
-
-  if (isolate->regexp_function()->initial_map() == receiver->map()) {
-    // Fast-path for unmodified JSRegExp instances.
-    return Just(true);
-  }
-
-  Handle<Object> match;
-  ASSIGN_RETURN_ON_EXCEPTION_VALUE(
-      isolate, match,
-      JSObject::GetProperty(receiver, isolate->factory()->match_symbol()),
-      Nothing<bool>());
-
-  if (!match->IsUndefined(isolate)) return Just(match->BooleanValue());
-  return Just(object->IsJSRegExp());
-}
-
 Object* Object::GetHash() {
   Object* hash = GetSimpleHash(this);
   if (hash->IsSmi()) return hash;