Move IsArgumentsMarker from class MaybeObject to Object.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index f4233e2d31c5853b7943470c2646ae2a732a1feb..3c9dc82351f1ba57a72e9e6c44fffbf5bde92b3d 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -423,11 +423,6 @@ bool MaybeObject::IsTheHole() {
 }
 
 
-bool MaybeObject::IsArgumentsMarker() {
-  return this == Heap::arguments_marker();
-}
-
-
 Failure* Failure::cast(MaybeObject* obj) {
   ASSERT(HAS_FAILURE_TAG(obj));
   return reinterpret_cast<Failure*>(obj);
@@ -735,6 +730,11 @@ bool Object::IsFalse() {
 }
 
 
+bool Object::IsArgumentsMarker() {
+  return this == Heap::arguments_marker();
+}
+
+
 double Object::Number() {
   ASSERT(IsNumber());
   return IsSmi()