[Bug libstdc++/81808] 27_io /basic_fstream/53984.cc failure on AIX

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81808

--- Comment #7 from David Edelsohn <dje at gcc dot gnu.org> ---
I have no objection to skipping the test on AIX if the test is not correct for
AIX behavior.