posix-test.lisp tests failed

[fourier]

Posix-dependent tests failing due to changes in osicat:

not ok 7 - Test islink
# Test samefile
    not ok 0 - Aborted due to an error in subtest "Test samefile"
    #    got: #:UNBOUND => #<SB-PCL::MISSING-SLOT ATIME {10052BB0B3}>
    #    expected: :NON-ERROR
not ok 8 - Test samefile
# Test sameopenfile
    not ok 0 - Aborted due to an error in subtest "Test sameopenfile"
    #    got: #:UNBOUND => #<SB-PCL::MISSING-SLOT ATIME {1005812873}>
    #    expected: :NON-ERROR
not ok 9 - Test sameopenfile