Bug 1332597 - IsMarked should return true for permanent atoms r=sfink a=abillings

js/src/gc/Marking.cpp

@@ -2685,6 +2685,8 @@ IsMarkedInternalCommon(T* thingp)
     CheckIsMarkedThing(thingp);
     MOZ_ASSERT(!IsInsideNursery(*thingp));
 
+    if (ThingIsPermanentAtomOrWellKnownSymbol(*thingp))
+        return true;
     Zone* zone = (*thingp)->asTenured().zoneFromAnyThread();
     if (!zone->isCollectingFromAnyThread() || zone->isGCFinished())
         return true;