Enable passing vfs2 tests.
Enable passing vfs2 tests.

I forgot to update getdents earlier. Several thousand runs of the fsync and
proc_net_unix tests all passed as well.

Updates #2923.

PiperOrigin-RevId: 317415488

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor