Add kNumberStringCacheRootIndex into writable_roots

src/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2882 matching lines @@
   isolate_->compilation_cache()->Clear();
 
   return true;
 }
 
 
 bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) {
   RootListIndex writable_roots[] = {
     kStoreBufferTopRootIndex,
     kStackLimitRootIndex,
+    kNumberStringCacheRootIndex,
     kInstanceofCacheFunctionRootIndex,
     kInstanceofCacheMapRootIndex,
     kInstanceofCacheAnswerRootIndex,
     kCodeStubsRootIndex,
     kNonMonomorphicCacheRootIndex,
     kPolymorphicCodeCacheRootIndex,
     kLastScriptIdRootIndex,
     kEmptyScriptRootIndex,
     kRealStackLimitRootIndex,
     kArgumentsAdaptorDeoptPCOffsetRootIndex,
@@ skipping 4560 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   memcpy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   memcpy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal