[ARM64] XPC services are unsupported on device.
[ARM64] XPC services are unsupported on device.

While around, clean up support for a 8 years old OS.

<rdar://problem/55916729>

git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@373510 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lldb,llvm-mirror/lldb,llvm-mirror/lldb,llvm-mirror/lldb,llvm-mirror/lldb