rs6000.c (rs6000_output_function_epilogue): Do not emit optional traceback table if optimize_size or TARGET_ELF.

        * config/rs6000/rs6000.c (rs6000_output_function_epilogue): Do not
        emit optional traceback table if optimize_size or TARGET_ELF.
        * config/rs6000/rs6000.md (prefetch): New.

From-SVN: r48865