output: elf -- Move common structures into outelf.h header
output: elf -- Move common structures into outelf.h header

All Elf formats we're supporting at the moment have
are using same structures, move them into a header
and name then with elf_ prefix.

This makes a few fields to carry 64 bit integers while
in former Elf32|x formats they can be 32 bit wide, but
I think it's acceptable tradeoff.

Signed-off-by: Cyrill Gorcunov <7a1ea01eee6961eb1e372e3508c2670446d086f4@gmail.com>

techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm