[runtime] [proxy] implement [[Construct]]

src/messages.h

 // Copyright 2006-2008 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.
 
 // The infrastructure used for (localized) message reporting in V8.
 //
 // Note: there's a big unresolved issue about ownership of the data
 // structures used by this framework.
 
 #ifndef V8_MESSAGES_H_
@@ skipping 190 matching lines @@
     "Proxy handler % returned non-configurable descriptor for property '%' "   \
     "from '%' trap")                                                           \
   T(ProxyRepeatedPropName, "Trap '%' returned repeated property name '%'")     \
   T(ProxyHandlerOrTargetRevoked,                                               \
     "Cannot create proxy with a revoked proxy as handler or target")           \
   T(ProxyRevoked, "Cannot perform '%' on a proxy that has been revoked")       \
   T(ProxyTargetNotExtensible, "Proxy target is not extensible")                \
   T(ProxyTargetNonObject, "Proxy target is non-object")                        \
   T(ProxyTargetPropNotConfigurable,                                            \
     "Proxy target property '%' is not configurable")                           \
+  T(ProxyTrapConstructMustReturnObject,                                        \
+    "Construct trap must return Object, but got ''%s'.")                       \
   T(ProxyTrapFunctionExpected,                                                 \
     "Proxy.createFunction called with non-function for '%' trap")              \
   T(ProxyTrapResultMustInclude, "Trap result must include %.")                 \
   T(ProxyTrapViolatesInvariant,                                                \
     "Result of trap '%' is inconsistent with proxy's target")                  \
   T(RedefineDisallowed, "Cannot redefine property: %")                         \
   T(RedefineExternalArray,                                                     \
     "Cannot redefine a property of an object with external array elements")    \
   T(ReduceNoInitial, "Reduce of empty array with no initial value")            \
   T(RegExpFlags,                                                               \
@@ skipping 298 matching lines @@
   static MUST_USE_RESULT MaybeHandle<String> GetStringifiedProperty(
       Isolate* isolate, LookupIterator* property_lookup,
       Handle<String> default_value);
 
   List<Handle<JSObject> > visited_;
 };
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_MESSAGES_H_