[builtins] Move StringIncludes to a builtin.

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 <memory>
 
@@ skipping 1358 matching lines @@
       Handle<Object> receiver, Handle<JSReceiver> setter, Handle<Object> value,
       ShouldThrow should_throw);
 
   MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
       Isolate* isolate, Handle<Object> object, uint32_t index);
 
   MUST_USE_RESULT static inline MaybeHandle<Object> SetElement(
       Isolate* isolate, Handle<Object> object, uint32_t index,
       Handle<Object> value, LanguageMode language_mode);
 
+  // ES#sec-isregexp IsRegExp ( argument )
+  // Includes checking of the mach property as per section 7.2.8 IsRegExp.
+  static Maybe<bool> IsRegExp(Isolate* isolate, Handle<Object> object);
+
   // Returns the permanent hash code associated with this object. May return
   // undefined if not yet created.
   Object* GetHash();
 
   // Returns the permanent hash code associated with this object depending on
   // the actual object type. May create and store a hash code if needed and none
   // exists.
   static Smi* GetOrCreateHash(Isolate* isolate, Handle<Object> object);
 
   // Checks whether this object has the same value as the given one.  This
@@ skipping 10053 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_