Track heap objects.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index d57a242513885e9bb3b0a78f61698248b815a0a9..a3fe10930c79f6117c21936e8350533ffcd87a30 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -2457,7 +2457,9 @@ LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
 
   LStoreNamedField* result =
       new(zone()) LStoreNamedField(obj, val, temp, temp_map);
-  if (FLAG_track_fields && instr->field_representation().IsSmi()) {
+  if ((FLAG_track_fields && instr->field_representation().IsSmi()) ||
+      (FLAG_track_heap_object_fields &&
+       instr->field_representation().IsHeapObject())) {
     return AssignEnvironment(result);
   }
   return result;