Ensure we can reliably check the cell for validity of global property

src/ic/x64/handler-compiler-x64.cc

Index: src/ic/x64/handler-compiler-x64.cc
diff --git a/src/ic/x64/handler-compiler-x64.cc b/src/ic/x64/handler-compiler-x64.cc
index 23882dcb5cb8e743828a4813eb8e201e00b6484a..f4eb22ebd072595b066cc8d73e380dd1e21b8fa5 100644
--- a/src/ic/x64/handler-compiler-x64.cc
+++ b/src/ic/x64/handler-compiler-x64.cc
@@ -501,7 +501,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
   // Log the check depth.
   LOG(isolate(), IntEvent("check-maps-depth", depth + 1));
 
-  if (depth != 0 || check == CHECK_ALL_MAPS) {
+  if (!current_map->IsJSGlobalObjectMap() &&
+      (depth != 0 || check == CHECK_ALL_MAPS)) {
     __ movp(scratch1, FieldOperand(reg, HeapObject::kMapOffset));
     Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
     __ CmpWeakValue(scratch1, cell, scratch2);
@@ -726,7 +727,7 @@ Register NamedStoreHandlerCompiler::value() {
 
 
 Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
-    Handle<PropertyCell> cell, Handle<Name> name, bool is_configurable) {
+    Handle<PropertyCell> cell, Handle<Name> name) {
   Label miss;
   if (IC::ICUseVector(kind())) {
     PushVectorAndSlot();
@@ -739,14 +740,8 @@ Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
   __ LoadWeakValue(result, weak_cell, &miss);
   __ movp(result, FieldOperand(result, PropertyCell::kValueOffset));
 
-  // Check for deleted property if property can actually be deleted.
-  if (is_configurable) {
-    __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
-    __ j(equal, &miss);
-  } else if (FLAG_debug_code) {
-    __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
-    __ Check(not_equal, kDontDeleteCellsCannotContainTheHole);
-  }
+  __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
+  __ j(equal, &miss);
 
   Counters* counters = isolate()->counters();
   __ IncrementCounter(counters->named_load_global_stub(), 1);