* corefile.c (num_of_syms_in): New function - computes the number

    * corefile.c (num_of_syms_in): New function - computes the number
        of symbols in a given file.
        (core_create_syms_from): New function - populates a symbol table
        from the symbols found in a specified file.
        * corefile.h: Prototype core_create_syms_from.
        * gprof.c (long_options): Add --external-symbol-table.
        (usage): Mention it.
        (main): Initiailize external_symbol_table from
        --external-symbol-table option.  If set use it.
        * gprof.texi: Document the new option.

        * NEWS: Mention new feature added to gprof.