--- old/src/hotspot/share/gc/g1/vmStructs_g1.hpp	2018-11-19 17:21:50.241566400 -0800
+++ new/src/hotspot/share/gc/g1/vmStructs_g1.hpp	2018-11-19 17:21:49.343830100 -0800
@@ -83,6 +83,7 @@
   declare_constant(HeapRegionType::StartsHumongousTag)                        \
   declare_constant(HeapRegionType::ContinuesHumongousTag)                     \
   declare_constant(HeapRegionType::OldMask)                                   \
+  declare_constant(HeapRegionType::PreMatureOldMask)                          \
   declare_constant(BarrierSet::G1BarrierSet)                                  \
   declare_constant(G1CardTable::g1_young_gen)