Add arc4random_addrandom binary compatibility.

This was in <stdlib.h> in older releases. It's no longer used, but we can
preserve backwards compatibility by making it a no-op.

(cherry-pick of 51c8355d5cf4b83ccd2ad250ca4c61a616356c2b.)

Bug: 16205834
Change-Id: Idde7b46df4f253e39675600bcf82352879a716e7
1 file changed