[proxies] Make Array.isArray respect proxies.

src/objects.h

 // Copyright 2012 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/allocation.h"
@@ skipping 1034 matching lines @@
   INLINE(bool IsFixedArrayBase() const);
   INLINE(bool IsExternal() const);
   INLINE(bool IsAccessorInfo() const);
 
   INLINE(bool IsStruct() const);
 #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) \
   INLINE(bool Is##Name() const);
   STRUCT_LIST(DECLARE_STRUCT_PREDICATE)
 #undef DECLARE_STRUCT_PREDICATE
 
+  // ES6, section 7.2.2 IsArray.  NOT to be confused with %_IsArray.
+  INLINE(Maybe<bool> IsArray() const);
+
   // ES6, section 7.2.3 IsCallable.
   INLINE(bool IsCallable() const);
 
   // ES6, section 7.2.4 IsConstructor.
   INLINE(bool IsConstructor() const);
 
   INLINE(bool IsTemplateInfo()) const;
   INLINE(bool IsNameDictionary() const);
   INLINE(bool IsGlobalDictionary() const);
   INLINE(bool IsSeededNumberDictionary() const);
@@ skipping 8416 matching lines @@
   DECL_ACCESSORS(handler, Object)
   // [target]: The target property.
   DECL_ACCESSORS(target, Object)
   // [hash]: The hash code property (undefined if not initialized yet).
   DECL_ACCESSORS(hash, Object)
 
   static MaybeHandle<Context> GetFunctionRealm(Handle<JSProxy> proxy);
 
   DECLARE_CAST(JSProxy)
 
-  bool IsRevoked();
+  bool IsRevoked() const;
 
   // ES6 9.5.1
   static MaybeHandle<Object> GetPrototype(Handle<JSProxy> receiver);
 
   // ES6 9.5.2
   MUST_USE_RESULT static Maybe<bool> SetPrototype(Handle<JSProxy> proxy,
                                                   Handle<Object> value,
                                                   bool from_javascript,
                                                   ShouldThrow should_throw);
   // ES6 9.5.3
@@ skipping 1206 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_