Version 5.1.281.20 (cherry-pick)

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 4caedf6cb092637ec640db33d6de8c4a5d2b6b91..34bb33b03d1b2fd617e4d38e0ada0a71237ea21b 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -2548,6 +2548,7 @@ bool Isolate::IsFastArrayConstructorPrototypeChainIntact() {
 }
 
 bool Isolate::IsArraySpeciesLookupChainIntact() {
+  if (!FLAG_harmony_species) return true;
   // Note: It would be nice to have debug checks to make sure that the
   // species protector is accurate, but this would be hard to do for most of
   // what the protector stands for:
@@ -2566,6 +2567,7 @@ bool Isolate::IsArraySpeciesLookupChainIntact() {
 }
 
 void Isolate::InvalidateArraySpeciesProtector() {
+  if (!FLAG_harmony_species) return;
   DCHECK(factory()->species_protector()->value()->IsSmi());
   DCHECK(IsArraySpeciesLookupChainIntact());
   PropertyCell::SetValueWithInvalidation(