function skipChainExpression(node) {
	return node && node.type === "ChainExpression" ? node.expression : node;
}
Retrieve `ChainExpression#expression` value if the given node a `ChainExpression` node. Otherwise, pass through it.
@param {ASTNode} node The node to address.
@returns {ASTNode} The `ChainExpression#expression` value if the node is a `ChainExpression` node. Otherwise, the node.