function readFloat64Body(bufferReader, name) {
  const start = bufferReader.index;
  const value = bufferReader.readFloat64(false); // big end

  if (value === 0) {
    // @ts-expect-error canonicalZero64 is a frozen array, not a Uint8Array
    if (!bufferReader.matchAt(start, canonicalZero64)) {
      throw Error(`Non-canonical zero at index ${start} of Syrup ${name}`);
    }
  }
  if (Number.isNaN(value)) {
    // @ts-expect-error canonicalNaN64 is a frozen array, not a Uint8Array
    if (!bufferReader.matchAt(start, canonicalNaN64)) {
      throw Error(`Non-canonical NaN at index ${start} of Syrup ${name}`);
    }
  }

  return value;
}
@param {BufferReader} bufferReader
@param {string} name