on int, but in fact it should operate on long.
- Introduce 'lvalue' variable, which is long.
- Fix _SC_XOPEN_SHM for 64bit archs.
- Fix _SC_PHYS_PAGES for 64bit archs.
Reported by: simokawa
- Use lvalue for pathconf(3), as it returns long.
- Cast value explicitly to long on return.