Revert "[lit] Generalized /dev/null support on Windows."

This reverts commit ca7fdbb974384ce5a05528b22a41d46b1cc13e92.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328596 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed