Simplify GetProperty helpers to ease element support

src/lookup.cc

Index: src/lookup.cc
diff --git a/src/lookup.cc b/src/lookup.cc
index 8eb5571e51e8dec93eae765b6bc79da9dd877097..79407d93ee6b4a398c0d6c25c3084f27580a5d31 100644
--- a/src/lookup.cc
+++ b/src/lookup.cc
@@ -355,7 +355,7 @@ void LookupIterator::WriteDataValue(Handle<Object> value) {
 
 
 bool LookupIterator::IsIntegerIndexedExotic(JSReceiver* holder) {
-  DCHECK(ExoticIndexState::kNotExotic != exotic_index_state_);
+  DCHECK(exotic_index_state_ != ExoticIndexState::kNotExotic);
   // Currently typed arrays are the only such objects.
   if (!holder->IsJSTypedArray()) return false;
   if (exotic_index_state_ == ExoticIndexState::kExotic) return true;
@@ -386,6 +386,14 @@ bool LookupIterator::HasInterceptor(Map* map) const {
 }
 
 
+Handle<InterceptorInfo> LookupIterator::GetInterceptor() const {
+  DCHECK_EQ(INTERCEPTOR, state_);
+  Handle<JSObject> js_holder = Handle<JSObject>::cast(holder_);
+  if (IsElement()) return handle(js_holder->GetIndexedInterceptor(), isolate_);
+  return handle(js_holder->GetNamedInterceptor(), isolate_);
+}
+
+
 bool LookupIterator::SkipInterceptor(JSObject* holder) {
   auto info = holder->GetNamedInterceptor();
   // TODO(dcarney): check for symbol/can_intercept_symbols here as well.