Remove Object::IsSpecObject, use Object::IsJSReceiver instead.

src/contexts.cc

Index: src/contexts.cc
diff --git a/src/contexts.cc b/src/contexts.cc
index 206f4a2e73d17015a17238610b63b92d7553c98b..50c4386a362f92dae9c36d99b75521aad25901f7 100644
--- a/src/contexts.cc
+++ b/src/contexts.cc
@@ -161,7 +161,7 @@ static Maybe<PropertyAttributes> UnscopableLookup(LookupIterator* it) {
   if (!maybe_unscopables.ToHandle(&unscopables)) {
     return Nothing<PropertyAttributes>();
   }
-  if (!unscopables->IsSpecObject()) return attrs;
+  if (!unscopables->IsJSReceiver()) return attrs;
   Handle<Object> blacklist;
   MaybeHandle<Object> maybe_blacklist =
       Object::GetProperty(unscopables, it->name());