Fix remaining issues in the custom snapshot.

src/serialize.cc

Index: src/serialize.cc
diff --git a/src/serialize.cc b/src/serialize.cc
index febb87b60c9bebed6cdcf0cefc3a683bbc94d16a..8d6d5508252450a24ef5810b414fa59f5c66fc84 100644
--- a/src/serialize.cc
+++ b/src/serialize.cc
@@ -1665,6 +1665,9 @@ void PartialSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
     DCHECK(Map::cast(obj)->code_cache() == obj->GetHeap()->empty_fixed_array());
   }
 
+  // Replace typed arrays by undefined.
+  if (obj->IsJSTypedArray()) obj = isolate_->heap()->undefined_value();
+
   int root_index = root_index_map_.Lookup(obj);
   if (root_index != RootIndexMap::kInvalidRootIndex) {
     PutRoot(root_index, obj, how_to_code, where_to_point, skip);
@@ -1832,6 +1835,9 @@ void Serializer::ObjectSerializer::Serialize() {
     PrintF("\n");
   }
 
+  // We cannot serialize typed array objects correctly.
+  DCHECK(!object_->IsJSTypedArray());
+
   if (object_->IsScript()) {
     // Clear cached line ends.
     Object* undefined = serializer_->isolate()->heap()->undefined_value();