Comment # 6 on bug 1155416 from Aaron Puchert

By the way, if your package uses CMake, such a patch might be accepted by
upstream:

# If not already there...
find_package(Clang CONFIG REQUIRED)

if (TARGET clang-cpp AND NOT TARGET clangBasic)
  target_link_libraries(... PRIVATE clang-cpp)
else()
  # Original code:
  target_link_libraries(...
    PRIVATE
    clangBasic
    ...
    )
endif()

That's pretty conservative and uses clang-cpp only if the component libraries
are not available.