* **Saturation**. applies to **all** LD/ST and Arithmetic and Logical
operations (without adding explicit saturation ops)
* **Reduction and Prefix-Sum** (Fibonnacci Series) Modes, including a
- "Reverse Gear" (running loops in reverse order).
+ "Reverse Gear" (running loops backwards).
* **vec2/3/4 "Packing" and "Unpacking"** (similar to VSX `vpack` and `vpkss`)
accessible in a way that is easier than REMAP, added for the same reasons
that drove `vpack` and `vpkss` etc. to be added: pixel, audio, and 3D