openssh should use its own arc4random.

Previously openssh was declaring its own arc4random but accidentally picking
up a lower-quality implementation from libc.

Bug: 14499627
Change-Id: Ie0c4ddb78101a666af3ec3eb9dc03c8fb44f6c4b
Don't build with strict aliasing for now.
Add option to force strict aliasing anyway.
This aliasing violation is being finnicky, make this a 'level 2' enable.