Remove code for non-clang frontends from pnacl build script
Remove code for non-clang frontends from pnacl build script

BUG= http://code.google.com/p/nativeclient/issues/detail?id=2697
Review URL: https://chromiumcodereview.appspot.com/9881001

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@8156 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

nacl-webkit/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client