message: remove obsolete HeapStatData comment about RawStatData
diff: @@ -52,19 +52,6 @@ public:
  StatName statName() const override { return this->data_.statName(); }
  };
  -// Partially implements a StatDataAllocator, leaving alloc & free for subclasses.
  -// We templatize on StatData rather than defining a virtual base StatData class
  -// for performance reasons; stat increment is on the hot path.
  -//
  -// The two production derivations cover using a fixed block of shared-memory for
  -// hot restart stat continuity, and heap allocation for more efficient RAM usage
  -// for when hot-restart is not required.
  -//
  -// Also note that RawStatData needs to live in a shared memory block, and it's
  -// possible, but not obvious, that a vptr would be usable across processes. In
  -// any case, RawStatData is allocated from a shared-memory block rather than via
  -// new, so the usual C++ compiler assistance for setting up vptrs will not be
  -// available. This could be resolved with placed new, or another nesting level.
  class HeapStatDataAllocator : public StatDataAllocatorImpl<HeapStatData> {
  public:
  HeapStatDataAllocator(SymbolTable& symbol_table) : StatDataAllocatorImpl(symbol_table) {}
  