Speculative fix for va_list/nullability test on Hexagon and PPC.
Speculative fix for va_list/nullability test on Hexagon and PPC.

PowerPC's va_list, at least, is a typedef for an array, which means it
decays to a pointer in parameter position. Since the decayed type is
built from the array element type, the typedef sugar is lost.

More rdar://problem/25846421.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@286533 91177308-0d34-0410-b5e6-96231b3b80d8

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