* NEWS: Mention new linker map file generation and the
--reduce-memory-overheads option.
* ld.texinfo: Document --reduce-memory-overheads option.
* ld.h (map_symbol_def): New struct.
(struct user_section_struct, section_userdata_type): Rename to:
(struct lean_user_section_struct, lean_section_userdata_type).
(struct fat_user_section_struct, fat_section_userdata_type): New.
(SECTION_USERDATA_SIZE): Define.
(args_type): New member reduce_memory_overheads.
* ldlang.c (map_obstack): New static variable.
(init_map_userdata, print_all_symbols, sort_def_symbol): New functions.
(lang_map): Unless command_line.reduce_memory_overheads is set,
initialize lists of defined symbols for each section.
(print_input_section): Unless command_line.reduce_memory_overheads
is set, use print_all_symbols.
(init_os): Use lean_section_userdata_type / SECTION_USERDATA_SIZE.
* ldmain.c (main): Initialize command_line.reduce_memory_overheads.
* lexsup.c (enum option_values): Add OPTION_REDUCE_MEMORY_OVERHEADS.
(ld_options): Add entry for --reduce-memory-overheads.
(parse_args): Handle OPTION_REDUCE_MEMORY_OVERHEADS.