const internal/syscall/unix.O_PATH

2 uses

	internal/syscall/unix (current package)
		at_sysnum_linux.go#L27: 	O_PATH = 0x200000
		fchmodat_linux.go#L27: 	fd, err := Openat(dirfd, path, O_PATH|syscall.O_NOFOLLOW|syscall.O_CLOEXEC, 0)