Add -Wl,--build-id=sha1 to the default LDFLAGS
    
    This is already the default for ld.bfd, so this is effectively a no-op
    for most packages.  However, lld defaults different build-id algorithm
    that the RPM build process does not support, so it needs this flag.
    
    This flag can be overriden by setting the %_build_id_flags macro,
    which packages could do if they wanted to use a more secure build-id
    algorithm.