function codeInBlock(unicode, ...blocknames) {
  if (blocknames.length === 0) return false;
  const [ lower, upper ] = codeRange(blocknames[0]) || [ -1, -1 ];
  return (unicode >= lower && unicode <= upper) 
    || codeInBlock(unicode, ...blocknames.slice(1));
}
Check if the code point is in the block
@param { number } unicode Unicode
@param { ...string } blocknames Names of the code blocks
@returns { boolean }