/usr/bin/clang-tblgen-3.9 is in libclang-common-3.9-dev 1:3.9.1-19ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../lib/llvm-3.9/bin/clang-tblgen
/usr/bin/../lib/llvm-3.9/bin/clang-tblgen