Patch by Anders Bergh:

'There's not much to say about this patch, it just adds the Arch Linux
gcc 4.3.1 header paths for i686 and amd64. The patch was generated
using "svn diff" with clang at revision 52660. The paths aren't
distribution-specific, so they should work for all Linux distributions
using the default(?) names like "i686-pc-linux-gnu".'

llvm-svn: 52665