function markAsUsed(node) {
			if (!node.label) {
				return;
			}

			const label = node.label.name;
			let info = scopeInfo;

			while (info) {
				if (info.label === label) {
					info.used = true;
					break;
				}
				info = info.upper;
			}
		}
Marks the label of a given node as used.
@param {ASTNode} node A node to mark. This is a BreakStatement or
     ContinueStatement.
@returns {void}