src/vs/base/common/strings.ts/firstNonWhitespaceIndex
export function firstNonWhitespaceIndex(str: string): number {
	for (let i = 0, len = str.length; i < len; i++) {
		const chCode = str.charCodeAt(i);
		if (chCode !== CharCode.Space && chCode !== CharCode.Tab) {
			return i;
		}
	}
	return -1;
}