add arch_elf64.c for x86_64, ported from sim/x86 Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
port optimized string functions for x86_64 from Bionic (BSD licensed) Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>