* addr2line.c (long_options): Add new option 'section'.
(usage): Document new -j/--section option.
(find_offset_in_section): New function.
(translate_addresses): Add 'section' parameter.
If it is non-null, call find_offset_in_section on it.
(process_file): Add 'section_name' parameter.
If it is non-null, look for the section in the BFD object.
Pass the section to translate_addresses.
(main): Handle new -j option.
Pass the section name to process_file.
* doc/binutils.texi (addr2line): Document new -j/--section option.