function readPlainDouble(reader, count) {
  const values = (reader.view.byteOffset + reader.offset) % 8
    ? new Float64Array(align(reader.view.buffer, reader.view.byteOffset + reader.offset, count * 8))
    : new Float64Array(reader.view.buffer, reader.view.byteOffset + reader.offset, count)
  reader.offset += count * 8
  return values
}
Read `count` double values.

@param {DataReader} reader
@param {number} count
@returns {Float64Array}