Pass dependency to HLoadNamedField for array length load

BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/267773004

Patch from Jing Bao <jing.bao@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21162 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -2145,7 +2145,7 @@ HInstruction* HGraphBuilder::BuildUncheckedMonomorphicElementAccess(
   HInstruction* length = NULL;
   if (is_js_array) {
     length = Add<HLoadNamedField>(
-        checked_object, static_cast<HValue*>(NULL),
+        checked_object->ActualValue(), checked_object,
         HObjectAccess::ForArrayLength(elements_kind));
   } else {
     length = AddLoadFixedArrayLength(elements);