libc: add eaccess() to run irb

eaccess() refer to access(2)

Signed-off-by: KANATSU Minoru <icc.pot.tyew272@gmail.com>
Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>