function hasStringLiteral(node) {
	if (isConcatenation(node)) {
		// `left` is deeper than `right` normally.
		return hasStringLiteral(node.right) || hasStringLiteral(node.left);
	}
	return astUtils.isStringLiteral(node);
}
Checks whether or not a given binary expression has string literals.
@param {ASTNode} node A node to check.
@returns {boolean} `true` if the node has string literals.