illumos gate

Linux introduced the getrandom(2) system call as a way to get at both /dev/random and /dev/urandom in a blocking and non-blocking fashion without the use of a file descriptor or hvaing /dev/ in a chroot. As part of support for the lx brand and for arc4random() we're adding a private system call for this function. At this time we're not making it a committed interface as we're waiting on determining where glibc and others expose it so as to maximize compatibility.

As part of this we're adding a new kcf routine which allows access to a blocking /dev/random similar to that which you can get from the /dev/random today if opened without O_NONBLOCK.