CMake: Force-link clang_rt.profile.a to LibC when building with coverage

This used to be in place until 671712c.

I had commented on that PR that "yeah should be good to remove". Turns
out that's not the case. A future patch to the clang driver might make
this obsolete :^).

Meta/CMake/utils.cmake

@@ -89,6 +89,9 @@ function(serenity_libc target_name fs_name)
  # Avoid creating a dependency cycle between system libraries and the C++ standard library. This is necessary
  # to ensure that initialization functions will be called in the right order (libc++ must come after LibPthread).
  target_link_options(${target_name} PRIVATE -static-libstdc++)
+ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang$" AND ENABLE_USERSPACE_COVERAGE_COLLECTION)
+ target_link_libraries(${target_name} PRIVATE clang_rt.profile)
+ endif()
  target_link_directories(LibC PUBLIC ${CMAKE_CURRENT_BINARY_DIR})
  serenity_generated_sources(${target_name})
 endfunction()