[llvm/f18] (9 commits) ...Merge branch 'f19' into f18

[Adam Jackson]

Summary of changes:

  c960848... add a hack to clang defaulting arm to hardfloat (*)
  4a3f435... fix old bogus date and drop llvm-3.2-clang-driver-secondary (*)
  bb18301... Tweak ld flags for memory usage and performance (*)
  6531bd7... Only build codegen backends for arches that actually exist  (*)
  94fba1f... Bump to LLVM 3.3svn (*)
  9b3371e... add snapshot scripts (*)
  069eca6... Enable aarch64 target (*)
  dd9e07d... llvm 3.3-rc2 (*)
  c1d649f... Merge branch 'f19' into f18

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