function create_selector(combinator, start) {
		return {
			type: 'RelativeSelector',
			combinator,
			selectors: [],
			start,
			end: -1,
			metadata: {
				is_global: false,
				is_global_like: false,
				scoped: false
			}
		};
	}
@param {AST.CSS.Combinator | null} combinator
@param {number} start
@returns {AST.CSS.RelativeSelector}