These date back to pre-git e1919611 in 1998.

More of these should be removed but the rdchk() test caused a timeout
on an ARM builder in Debian. It might just be a fluke but the tests are
pointless regardless.

See also 16eb8005 "build: Remove tests for
getdents() and getdirentries()"

Signed-off-by: Mathieu Parent <math.parent@gmail.com>