* master:
  fixup! rename NodeAttr to StableAttr
  rename NodeAttr to StableAttr
  internal: fix access for root user
  tarfs: handle empty directories, handle more file types
  nodefs: add Attr to MemSymlink
  nodefs: protect dirsteam overflow with lock
  nodefs: add TestReadDirStress
  nodefs: protect against double close
  newunionfs: run PosixTest tests.
  newunionfs: symlink/readlink
  posixtest: export list of tests
  nodefs: handle unimplemented Mkdir
  newunionfs: a new unionfs implementation
  fuse: fix SupportsVersion
  nodefs: skip tests if kernel doesn't support lseek/copy_file_range
  posixtest: new package for generic file system tests
  update go modules.
  nodefs: add EntryOut to Create signature
  nodefs: add Inode.IsDir
  nodefs: implement Setattr in loopback