Revert "[IA64] Unwire set/get_robust_list"
This reverts commit 2636255488484e04d6d54303d2b0ec30f7ef7e02.
Jakub Jelinek provided the missing futex_atomic_cmpxchg_inatomic()
function, so now it should be safe to re-enable these syscalls.
Signed-off-by: Tony Luck <tony.luck@intel.com>