message: miniheap: make the atomically-updated members actually atomic
diff: @@ -179,7 +179,7 @@ public:
  inline bool isMeshingCandidate() const {
  if (_refCount > 0)
  - mesh::debug("skipping due to MH reference (%zu)", _refCount);
  + mesh::debug("skipping due to MH reference (%zu)", _refCount.load());
  return !isAttached() && _refCount == 0 && objectSize() < 4096;
  }
  @@ -376,9 +376,9 @@ protected:
  char *_span[kMaxMeshes];
  internal::BinToken _token;
  - uint32_t _inUseCount{0}; // 60
  + atomic<uint32_t> _inUseCount{0}; // 60
  - mutable uint32_t _refCount{0};
  + mutable atomic<uint32_t> _refCount{0};
  uint32_t _meshCount; // : 7;
  #ifdef MESH_EXTRA_BITS
  internal::Bitmap _bitmap0; // 16 bytes
  @@ -388,6 +388,8 @@ protected:
  #endif
  };
  +static_assert(sizeof(pthread_t) == 8, "pthread_t too big");
  +
  static_assert(sizeof(mesh::internal::Bitmap) == 16, "Bitmap too big!");
  #ifdef MESH_EXTRA_BITS
  static_assert(sizeof(MiniHeap) == 168, "MiniHeap too big!");
  