PNaCl: Disallow the IRT semaphore interface, now that libpthread doesn't use it
PNaCl: Disallow the IRT semaphore interface, now that libpthread doesn't use it

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3484
TEST=PNaCl toolchain trybots

Review URL: https://codereview.chromium.org/18421005

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@11750 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

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