generic/45[34]: add detection of confusable variation sequences

generic/45[34]: add detection of confusable variation sequences

ArsTechnica recently wrote about a GitHub supply chain attack wherein
non-rendering unicode sequences were embedded in javascript files to
hide payloads that could be decrypted trivially later.  While these are
unlikely to appear in file and attribute names, xfs_scrub will warn about
this sort of steganography, so let's make sure it works.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Zorro Lang <zlang@kernel.org>
Signed-off-by: Zorro Lang <zlang@kernel.org>