[ThinLTO] XFAIL path manipulation test on Windows

This test is creating and checking paths using '/'. XFAIL it on Windows
to unbreak bot:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/5478

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269775 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed