We currently get boolean attributes in bulk and call something like this to get to a particular attribute:

(fs.getBooleanAttributes(f) & FileSystem.BA_EXISTS) != 0

By instead providing a utility that takes the attribute value, we can simplify the logic at call-sites a bit:

fs.getBooleanAttribute(f, FileSystem.BA_EXISTS)

This also allows for an optimization since UnixFileSystem.getBooleanAttributes slices out and read the BA_HIDDEN bit from the name.