make LIBCXXABI_NORETURN be the right attribute
make LIBCXXABI_NORETURN be the right attribute

git-svn-id: 6a9f6578bdee8d959f0ed58970538b4ab6004734@136680 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi