Remove clang-3.[789] from OS versions with SDKs that require functionality not in those compilers
Remove clang-3.[789] from OS versions with SDKs that require functionality not in those compilers

Fixes https://trac.macports.org/ticket/54504

Signed-off-by: Jeremy Huddleston Sequoia <db3cec0cba09acb9cf8fd8bd399a3b27498cf883@macports.org>

macports/macports-base,neverpanic/macports-base,macports/macports-base,danchr/macports-base,danchr/macports-base,neverpanic/macports-base