/usr/lib/llvm-6.0/lib/cmake/ is in llvm-6.0-dev 1:6.0-1ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/llvm-6.0/lib/cmake/llvm/
/usr/lib/llvm-6.0/lib/cmake/llvm/AddLLVM.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/AddLLVMDefinitions.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/AddOCaml.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/AddSphinxTarget.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/CheckAtomic.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/CheckCompilerVersion.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/CheckLinkerFlag.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/ChooseMSVCCRT.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/CrossCompile.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/DetermineGCCCompatible.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/FindOCaml.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/FindSphinx.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/GenerateVersionFromCVS.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/GetSVN.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/HandleLLVMOptions.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/HandleLLVMStdlib.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVM-Config.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVMConfig.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVMConfigVersion.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVMExports-relwithdebinfo.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVMExports.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVMExternalProjectUtils.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVMInstallSymlink.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/LLVMProcessSources.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/TableGen.cmake
/usr/lib/llvm-6.0/lib/cmake/llvm/VersionFromVCS.cmake