Additional affine If simplification (#259)

* If simplification pt 2

* fix bug

* More affine simplifications

* Fix bug

* Affine par simplifications

* Fix bug

* unsigned affine cfg

* Add if par merge

* More tests

* Aggressive loop if simplification

* Single var elim

* Fix op interop

* Simplify if

* Add else check

* Fix wrong affine if condition

* Fix bug with considering condition of if to be true in else region

* Add test

Co-authored-by: Ivan Radanov Ivanov <[email protected]>

Author: wsmoses