[builtins] Migrate Object.keys to C++.

src/execution.cc

 // Copyright 2014 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.
 
 #include "src/execution.h"
 
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
 #include "src/isolate-inl.h"
 #include "src/messages.h"
@@ skipping 403 matching lines @@
   // You should hold the ExecutionAccess lock when you call this.
   if (stored_limit != 0) {
     SetStackLimit(stored_limit);
   }
 }
 
 
 // --- C a l l s   t o   n a t i v e s ---
 
 
-MaybeHandle<Object> Execution::ToObject(Isolate* isolate, Handle<Object> obj) {
+MaybeHandle<JSReceiver> Execution::ToObject(Isolate* isolate,
+                                            Handle<Object> obj) {
   Handle<JSReceiver> receiver;
   if (JSReceiver::ToObject(isolate, obj).ToHandle(&receiver)) {
     return receiver;
   }
-  THROW_NEW_ERROR(
-      isolate, NewTypeError(MessageTemplate::kUndefinedOrNullToObject), Object);
+  THROW_NEW_ERROR(isolate,
+                  NewTypeError(MessageTemplate::kUndefinedOrNullToObject),
+                  JSReceiver);
 }
 
 
 Handle<String> Execution::GetStackTraceLine(Handle<Object> recv,
                                             Handle<JSFunction> fun,
                                             Handle<Object> pos,
                                             Handle<Object> is_global) {
   Isolate* isolate = fun->GetIsolate();
   Handle<Object> args[] = { recv, fun, pos, is_global };
   MaybeHandle<Object> maybe_result =
@@ skipping 49 matching lines @@
 
   isolate_->counters()->stack_interrupts()->Increment();
   isolate_->counters()->runtime_profiler_ticks()->Increment();
   isolate_->runtime_profiler()->OptimizeNow();
 
   return isolate_->heap()->undefined_value();
 }
 
 }  // namespace internal
 }  // namespace v8