X86: move test requiring X86TargetLowering info into its own directory
    
If LLVM is built without X86 as a supported target then the test would
mysteriously fail.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201668 91177308-0d34-0410-b5e6-96231b3b80d8