[CUDA] Attempt to fix test failures in cuda-macos-includes.cu.
[CUDA] Attempt to fix test failures in cuda-macos-includes.cu.

Run clang -cc1 -E instead of -S, in an attempt to make this test work
cross-platform.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@287292 91177308-0d34-0410-b5e6-96231b3b80d8

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