Function add

test/html5lib.spectest.js:106–109

(i, line)

			 * @param {string} line message
			 */
			const add = (i, line) => {
				if (!internalByEntry.has(i)) internalByEntry.set(i, []);
				internalByEntry.get(i).push(line);
			};
			if (err) {
				// Compiler-level throw can't be attributed to one entry; mark all.
				const line = String(err.message).split("\n")[0].slice(0, 160);