linux26: add linux-isms from posix.vapi; add eventfd
linux26: add linux-isms from posix.vapi; add eventfd

slyon/debian-fso-deviced,slyon/debian-libfsoframework,slyon/debian-fso-deviced,slyon/debian-fso-usaged,slyon/debian-fso-usaged,slyon/debian-libfsoframework