[es6] Reintroduce the instanceof operator in the backends.

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 1215 matching lines @@
   MUST_USE_RESULT static MaybeHandle<Object> BitwiseAnd(Isolate* isolate,
                                                         Handle<Object> lhs,
                                                         Handle<Object> rhs);
   MUST_USE_RESULT static MaybeHandle<Object> BitwiseOr(Isolate* isolate,
                                                        Handle<Object> lhs,
                                                        Handle<Object> rhs);
   MUST_USE_RESULT static MaybeHandle<Object> BitwiseXor(Isolate* isolate,
                                                         Handle<Object> lhs,
                                                         Handle<Object> rhs);
 
+  // ES6 section 7.3.19 OrdinaryHasInstance (C, O).
+  MUST_USE_RESULT static MaybeHandle<Object> OrdinaryHasInstance(
+      Isolate* isolate, Handle<Object> callable, Handle<Object> object);
+
+  // ES6 section 12.10.4 Runtime Semantics: InstanceofOperator(O, C)
+  MUST_USE_RESULT static MaybeHandle<Object> InstanceOf(
+      Isolate* isolate, Handle<Object> object, Handle<Object> callable);
+
   MUST_USE_RESULT static MaybeHandle<Object> GetProperty(LookupIterator* it);
 
   // ES6 [[Set]] (when passed DONT_THROW)
   // Invariants for this and related functions (unless stated otherwise):
   // 1) When the result is Nothing, an exception is pending.
   // 2) When passed THROW_ON_ERROR, the result is never Just(false).
   // In some cases, an exception is thrown regardless of the ShouldThrow
   // argument.  These cases are either in accordance with the spec or not
   // covered by it (eg., concerning API callbacks).
   MUST_USE_RESULT static Maybe<bool> SetProperty(LookupIterator* it,
@@ skipping 9495 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_