Relax this test so it also works on platforms that use characters other than forward slashes as path separators.
Relax this test so it also works on platforms that use characters other
than forward slashes as path separators.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@241090 91177308-0d34-0410-b5e6-96231b3b80d8

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