Remove all uses of field-tracking flags that do not make decisions but are subject to existing info…

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 306042f4ea65601e0e4ed3c5fe57ee08937be87c..69035d62d662d909d0d1ac630dacae0e6febbd15 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -4950,8 +4950,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_KeyedGetProperty) {
           int offset = result.GetFieldIndex().field_index();
           // Do not track double fields in the keyed lookup cache. Reading
           // double values requires boxing.
-          if (!FLAG_track_double_fields ||
-              !result.representation().IsDouble()) {
+          if (!result.representation().IsDouble()) {
             keyed_lookup_cache->Update(receiver_map, key, offset);
           }
           return receiver->FastPropertyAt(result.representation(), offset);