message: thread-local-heap: ensure size class 0 is initialized
diff: @@ -41,7 +41,8 @@ public:
  : _prng(internal::seed(), internal::seed()),
  _global(global),
  _maxObjectSize(SizeMap::ByteSizeForClass(kNumBins - 1)) {
  - // start at 1, becuase 0 is an unused '0' size class
  + // when asked, give 16-byte allocations for 0-byte requests
  + _freelist[0].setObjectSize(SizeMap::ByteSizeForClass(1));
  for (size_t i = 1; i < kNumBins; i++) {
  _freelist[i].setObjectSize(SizeMap::ByteSizeForClass(i));
  }
  