Make function proxies work as constructors.

src/heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3464 matching lines @@
 
   // Reset the map for the object.
   object->set_map(map);
 
   // Reinitialize the object from the constructor map.
   InitializeJSObjectFromMap(JSObject::cast(object),
                             FixedArray::cast(properties), map);
 
   // Functions require some minimal initialization.
   if (type == JS_FUNCTION_TYPE) {
+    map->set_function_with_prototype(true);
     String* name;
     MaybeObject* maybe_name = LookupAsciiSymbol("<freezing call trap>");
     if (!maybe_name->To<String>(&name)) return maybe_name;
     SharedFunctionInfo* shared;
     MaybeObject* maybe_shared = AllocateSharedFunctionInfo(name);
     if (!maybe_shared->To<SharedFunctionInfo>(&shared)) return maybe_shared;
     JSFunction* func;
     MaybeObject* maybe_func =
         InitializeFunction(JSFunction::cast(object), shared, the_hole_value());
     if (!maybe_func->To<JSFunction>(&func)) return maybe_func;
@@ skipping 2608 matching lines @@
 }
 
 
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 } }  // namespace v8::internal