Fix assertion failure relaxing TLS for position-independent executables.
    
    gold/
    	PR gold/21444
    	* gold.cc (Target_sparc::Relocate::relocate_tls): Local
    	variables are final for position-independent executables. This
    	has to be consistent with Target_sparc::Scan::local otherwise
    	they will disagree as to whether local-exec is used.