[builtins] Move StringIncludes to a builtin.

src/objects.cc

 // 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.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 1959 matching lines @@
     uint32_t hash = Simd128Value::cast(object)->Hash();
     return Smi::FromInt(hash & Smi::kMaxValue);
   }
   DCHECK(object->IsJSReceiver());
   // Simply return the receiver as it is guaranteed to not be a SMI.
   return 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;
 
   DisallowHeapAllocation no_gc;
   DCHECK(IsJSReceiver());
   JSReceiver* receiver = JSReceiver::cast(this);
   Isolate* isolate = receiver->GetIsolate();
   return JSReceiver::GetIdentityHash(isolate, handle(receiver, isolate));
 }
@@ skipping 18106 matching lines @@
         ns, Accessors::ModuleNamespaceEntryInfo(isolate, name, attr))
         .Check();
   }
   JSObject::PreventExtensions(ns, THROW_ON_ERROR).ToChecked();
 
   return ns;
 }
 
 }  // namespace internal
 }  // namespace v8