Mark test as XFAIL instead of disabling it everywhere.

There is no lit feature 'X86' so this test is just disabled completely.
Make it XFAIL until a solution is found.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279966 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed