Enable clang build of libstdc++
Enable clang build of libstdc++

update llvm-gcc stable rev to include:
http://codereview.chromium.org/8380016/

BUG= http://code.google.com/p/nativeclient/issues/detail?id=2289 

BUG= http://code.google.com/p/nativeclient/issues/detail?id=2344
Review URL: http://codereview.chromium.org/8382016

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@7020 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

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