Use C++ implementation of Object.definePropert{y,ies}

test/cctest/test-api.cc

 // Copyright 2012 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 8710 matching lines @@
   CompileRun("Object.seal(other)");
   ExpectTrue("Object.isExtensible(other)");
 
   // Regression test for issue 1250.
   // Make sure that we can set the accessible accessors value using normal
   // assignment.
   CompileRun("other.accessible_prop = 42");
   CHECK_EQ(42, g_echo_value);
 
   v8::Handle<Value> value;
-  CompileRun("Object.defineProperty(other, 'accessible_prop', {value: -1})");
-  value = CompileRun("other.accessible_prop == 42");
+  CompileRun("Object.defineProperty(other, 'accessible_prop', {value: 43})");
+  value = CompileRun("other.accessible_prop == 43");
   CHECK(value->IsTrue());
+  CHECK_EQ(43, g_echo_value);  // Make sure we didn't overwrite the setter.
 }
 
 
 static bool AccessAlwaysBlocked(Local<v8::Object> global, Local<Value> name,
                                 v8::AccessType type, Local<Value> data) {
   i::PrintF("Access blocked.\n");
   return false;
 }
 
 
@@ skipping 13196 matching lines @@
   LocalContext env;
 
   env->Global()->Set(v8_str("keys"), v8::Array::GetKeysIterator(isolate));
   env->Global()->Set(v8_str("values"), v8::Array::GetValuesIterator(isolate));
   env->Global()->Set(v8_str("entries"), v8::Array::GetEntriesIterator(isolate));
 
   ExpectString("typeof keys", "function");
   ExpectString("typeof values", "function");
   ExpectString("typeof entries", "function");
 }