Fix emulation of SASX and SSAX instructions.

I'd suspected for a while that these ops were incorrectly emulated and finally got around to doing tests for them.

- SASX
  - What the hardware printed ![SASXCorrect](http://i.imgur.com/cAxDk7S.jpg)
  - What the emulator printed ![SASXIncorrect](http://i.imgur.com/0NM1fMj.png)

- SSAX
  - What the hardware printed: ![SSAXCorrect](http://i.imgur.com/nWXId6X.jpg)
  - What the emulator printed ![SSAXIncorrect](http://i.imgur.com/obkYz8o.png)

This pull request corrects these instructions.

Ignore the "SUCCESS" printout for the obviously wrong results. I just used the testing framework to quickly provide a direct printout on screen.