message: hdf5: mapping to IOType isn't needed anymore
  All of the core is using stdint types already, so this isn't needed
  anymore.
diff: @@ -871,16 +871,15 @@ void HDF5Common::AddNonStringAttribute(core::IO &io,
  hid_t attrId, hid_t h5Type,
  hsize_t arraySize)
  {
  - using IOType = typename TypeInfo<T>::IOType;
  if (arraySize == 0)
  { // SCALAR
  - IOType val;
  + T val;
  H5Aread(attrId, h5Type, &val);
  io.DefineAttribute(attrName, val);
  }
  else
  {
  - IOType val[arraySize];
  + T val[arraySize];
  H5Aread(attrId, h5Type, val);
  io.DefineAttribute(attrName, val, arraySize);
  }
  