Fix warnings that appear during the build of the llvm package
    
    The package redefines %optflags on i686 and s390x, so the
    %__build_for_lang_* macros are no longer expanded, triggering
    a warning from RPM (“%__build_for_lang_any defined but not
    used within scope”).  Clang warns about -Wno-complain-wrong-lang
    with -Wall, so the warning option is suppressed for
    "%toolchain" != "gcc".
    
    Reported-by: Tulio Magno Quites Machado Filho <tuliom@ascii.art.br>