[test] Un-XFAIL test that is now passing

Author: lorentey

test/Interop/Cxx/class/move-only/move-only-cxx-value-type.swift

@@ -4,9 +4,6 @@
 //
 // REQUIRES: executable_test
 
-// Needs an UnsafeMutablePointer where Pointee: ~Copyable (rdar://124544696)
-// XFAIL: *
-
 import MoveOnlyCxxValueType
 import StdlibUnittest