Fix #170: Move get-system-info to C
- Define
os_get_system_info
in os-common.c to return the desired system info. - Add
get-system-info
to unix.lisp to call os_get_system_info. - Remove
get-system-info
from linux-os.lisp
The return type of get-system-info
is slightly changed
to `(values (signed-byte 64) (signed-byte 64) (signed-byte 32))