message: Throw an error when GathervArrays() is asked to gather more than 2^31 bytes.
diff: @@ -63,7 +63,8 @@ void Comm::GathervArrays(const T *source, size_t sourceCount,
  displs[countsSize - 1] + counts[countsSize - 1];
  if (totalElements > 2147483648)
  {
  - std::runtime_error(
  + helper::ThrowNested<std::runtime_error>(
  + "Helper", "adiosComm", "GathervVectors",
  "ERROR: GathervArrays does not support gathering more than "
  "2^31 elements. Here it was tasked with " +
  std::to_string(totalElements) + " elements\n");
  