invalid directives can occur in #if 0 code, just pass them through like other directives PTH doesn't care about.  This should fix rdar://6804029
invalid directives can occur in #if 0 code, just pass them
through like other directives PTH doesn't care about.  This
should fix rdar://6804029


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@69524 91177308-0d34-0410-b5e6-96231b3b80d8

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