[alex/f15] (4 commits) ...Merge remote-tracking branch 'refs/remotes/origin/f16' into f15

[Jens Petersen]

Summary of changes:

  c51ac07... BR ghc-Cabal-devel and use ghc_excluded_archs (*)
  d905708... ghc_arches replaces ghc_excluded_archs (*)
  8450398... Reverting "add ARM" to backport newer changes from f16 bran
  beffe14... Merge remote-tracking branch 'refs/remotes/origin/f16' into

(*) This commit already existed in another branch; no separate mail sent