make nexe from pexe and re-enable test during bitcode build
make nexe from pexe and re-enable test during bitcode build

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3318

Review URL: https://codereview.chromium.org/12660009

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@10982 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client