Driver: cleanup /vd2 test
Driver: cleanup /vd2 test

/vd2 is not ignored anymore, remove it from the ignored list.

Add a test to ensure that it does the right thing.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@204563 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang