--- old/src/hotspot/share/gc/g1/g1HeapRegionTraceType.hpp	2018-10-05 11:09:28.555194500 -0700
+++ new/src/hotspot/share/gc/g1/g1HeapRegionTraceType.hpp	2018-10-05 11:09:27.693392800 -0700
@@ -37,6 +37,7 @@
     StartsHumongous,
     ContinuesHumongous,
     Old,
+    PreMatureOld,
     OpenArchive,
     ClosedArchive,
     G1HeapRegionTypeEndSentinel
@@ -50,6 +51,7 @@
       case StartsHumongous:    return "Starts Humongous";
       case ContinuesHumongous: return "Continues Humongous";
       case Old:                return "Old";
+      case PreMatureOld:       return "PreMatureOld";
       case OpenArchive:        return "OpenArchive";
       case ClosedArchive:      return "ClosedArchive";
       default: ShouldNotReachHere(); return NULL;