iwyu: Require llvm+all_targets on non-x86_64 systems (#18710)
iwyu: Require llvm+all_targets on non-x86_64 systems (#18710)


iulian787/spack,iulian787/spack,LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack,iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack