function getPlaceholderPath(cwd) {
	return path.join(cwd, "__placeholder__.js");
}
Return the absolute path of a file named `"__placeholder__.js"` in a given directory.
This is used as a replacement for a missing file path.
@param {string} cwd An absolute directory path.
@returns {string} The absolute path of a file named `"__placeholder__.js"` in the given directory.