Merge branch 'tb/test-apfs-utf8-normalization'

A test to see if the filesystem normalizes UTF-8 filename has been
updated to check what we need to know in a more direct way, i.e. a
path created in NFC form can be accessed with NFD form (or vice
versa) to cope with APFS as well as HFS.

* tb/test-apfs-utf8-normalization:
  test: correct detection of UTF8_NFD_TO_NFC for APFS

diff --cc t/test-lib.sh
Simple merge