Allow Object.defineProperty to update value of an API accessor.

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 9378 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_1);
 
   v8::Handle<Value> value;
-  // We follow Safari in ignoring assignments to host object accessors.
   CompileRun("Object.defineProperty(other, 'accessible_prop', {value: -1})");
   value = CompileRun("other.accessible_prop == 42");
   CHECK(value->IsTrue());
 }
 
 
 static bool GetOwnPropertyNamesNamedBlocker(Local<v8::Object> global,
                                             Local<Value> name,
                                             v8::AccessType type,
                                             Local<Value> data) {
@@ skipping 13082 matching lines @@
   v8::internal::FLAG_stack_size = 150;
   LocalContext current;
   v8::Isolate* isolate = current->GetIsolate();
   v8::HandleScope scope(isolate);
   V8::SetCaptureStackTraceForUncaughtExceptions(
       true, 10, v8::StackTrace::kDetailed);
   v8::TryCatch try_catch;
   CompileRun("(function f(x) { f(x+1); })(0)");
   CHECK(try_catch.HasCaught());
 }