XFAIL test that's inappropriate for AArch64 ABI
XFAIL test that's inappropriate for AArch64 ABI

Only some ABIs require the "signext" attribute on parameters. On most
platforms, however, it's a useful test so it's best not to limit it to some
random arbitrary platform.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@174619 91177308-0d34-0410-b5e6-96231b3b80d8

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