Unify markbits for old and new spaces.

src/serialize.cc

Index: src/serialize.cc
diff --git a/src/serialize.cc b/src/serialize.cc
index 55f747926941058ae59023c9052376a8cf65d66d..aba36aaf7db5d873d54ccb900f1d6b0092434877 100644
--- a/src/serialize.cc
+++ b/src/serialize.cc
@@ -397,17 +397,13 @@ void ExternalReferenceTable::PopulateTable(Isolate* isolate) {
       UNCLASSIFIED,
       11,
       "Heap::NewSpaceMask()");
-  Add(ExternalReference::new_space_mark_bits(isolate).address(),
-      UNCLASSIFIED,
-      12,
-      "Marking::new_space_bitmap()");
   Add(ExternalReference::heap_always_allocate_scope_depth(isolate).address(),
       UNCLASSIFIED,
-      13,
+      12,
       "Heap::always_allocate_scope_depth()");
   Add(ExternalReference::new_space_allocation_limit_address(isolate).address(),
       UNCLASSIFIED,
-      14,
+      13,
       "Heap::NewSpaceAllocationLimitAddress()");
   Add(ExternalReference::new_space_allocation_top_address(isolate).address(),
       UNCLASSIFIED,