This file is indexed.

/usr/lib/clang/4.0.0/include is in libclang-common-4.0-dev 1:4.0-1ubuntu1~16.04.2.

This file is owned by root:root, with mode 0o777.

It is a symlink to /usr/lib/clang/4.0.0/../../llvm-4.0/lib/clang/4.0.0/include