correctly invalidate global cells

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 7a4322139d68405f408cccd558836f0ec3d5c0dc..fba3c66dac1a447bd32c31b508b791a3be125ee4 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -5348,9 +5348,9 @@ void HOptimizedGraphBuilder::VisitVariableProxy(VariableProxy* expr) {
 
       if (type == kUseCell) {
         Handle<PropertyCell> cell = it.GetPropertyCell();
-        if (cell->type()->IsConstant()) {
-          PropertyCell::AddDependentCompilationInfo(cell, top_info());
-          Handle<Object> constant_object = cell->type()->AsConstant()->Value();
+        PropertyCell::AddDependentCompilationInfo(cell, top_info());
+        if (it.property_details().cell_type() == PropertyCellType::kConstant) {
+          Handle<Object> constant_object(cell->value(), isolate());
           if (constant_object->IsConsString()) {
             constant_object =
                 String::Flatten(Handle<String>::cast(constant_object));
@@ -6514,8 +6514,9 @@ void HOptimizedGraphBuilder::HandleGlobalVariableAssignment(
   GlobalPropertyAccess type = LookupGlobalProperty(var, &it, STORE);
   if (type == kUseCell) {
     Handle<PropertyCell> cell = it.GetPropertyCell();
-    if (cell->type()->IsConstant()) {
-      Handle<Object> constant = cell->type()->AsConstant()->Value();
+    PropertyCell::AddDependentCompilationInfo(cell, top_info());
+    if (it.property_details().cell_type() == PropertyCellType::kConstant) {
+      Handle<Object> constant(cell->value(), isolate());
       if (value->IsConstant()) {
         HConstant* c_value = HConstant::cast(value);
         if (!constant.is_identical_to(c_value->handle(isolate()))) {