Function _isNewline

lib/css/syntax.js:268–269

(cc)

 * @returns {boolean} true, if cc is a newline (per the spec: LF, CR, or FF)
 */
const _isNewline = (cc) =>
	cc === CC_LINE_FEED || cc === CC_CARRIAGE_RETURN || cc === CC_FORM_FEED;

/**
 * If the source had a CR followed by an LF, advance past the LF —