(gld${EMULATION_NAME}_add_options): Add new --exclude-all-symbols option
        to exclude all symbols from automatic export.
        (gld_${EMULATION_NAME}_list_options): Describe it.
        (gld${EMULATION_NAME}_handle_option): Handle it.
        * emultempl/pep.em: Likewise to all the above.
        * pe-dll.c (pe_dll_exclude_all_symbols): New variable.
        (process_def_file_and_drectve): Use it.
        * pe-dll.h (pe_dll_exclude_all_symbols): Declare.
        * pep-dll.c (pep_dll_exclude_all_symbols): Define pep_ alias.
        * pep-dll.h (pe_dll_exclude_all_symbols): Declare.
        * NEWS: Mention the new feature.
        * ld.texinfo: Document the new command line switch.