src/vs/editor/common/commands/shiftCommand.ts/cachedStringRepeat
function cachedStringRepeat(str: string, count: number): string {
	if (count <= 0) {
		return '';
	}
	if (!repeatCache[str]) {
		repeatCache[str] = ['', str];
	}
	const cache = repeatCache[str];
	for (let i = cache.length; i <= count; i++) {
		cache[i] = cache[i - 1] + str;
	}
	return cache[count];
}