rs6000.c (current_file_function_operand): Return zero for weak functions.

        * rs6000.c (current_file_function_operand): Return zero for
        weak functions.
        (rs6000_encode_section_info): Do not set SYMBOL_REF_FLAG for
        weak symbols.
        * rs6000.h (ENCODE_SECTION_NIFO): Do not set SYMBOL_REF_FLAG
        for weak symbols.

From-SVN: r28527