llvm: make use of compound licenses

  llvm_meta = {

    license =

      with lib.licenses;

      [ ncsa ]

      ++

      # Contributions after June 1st, 2024 are only licensed under asl20 and

      # llvm-exception: https://github.com/llvm/llvm-project/pull/92394

        lib.optionals (lib.versionAtLeast release_version "19") [

          asl20

          llvm-exception

        ];

      if lib.versionAtLeast release_version "19" then

        AND [

          ncsa

          (WITH asl20 llvm-exception)

        ]

      else

        ncsa;

    teams = [

      lib.teams.llvm

      lib.teams.security-review

    ];

    # See llvm/cmake/config-ix.cmake.

    platforms =

      lib.platforms.aarch64