Include reloc.h and elf_abi.h.
(rel_dyn_section, dynstr_section, dynsym_section): New variables.
(old_data_scnhdr): New variable.
(CHECK_SCNHDR): Compare just 8 chars of section name.
(unexec): Check for rel_dyn_section, dynsym_section, dynstr_section.
Do call update_dynamic_symbols.
(update_dynamic_symbols): Finish it up and take away #if 0.
(unexec): Do CHECH_SCNHDR on _RCONST if that's defined.
Ignore rdata_section if there is none.
(update_dynamic_symbols): New arg new_name. Call changed.
Fix some calls to WRITE.
(fatal_unexec): Declare all arguments.