First Draft: Static Single Assignment

[Walter Bright]

On 11/27/2025 2:14 PM, Peter C wrote:
> Compound assignment on a primitive type suggests an intention to mutate, not 
> reassign. So to maintain conceptual consistency, compound assignments should 
> also be allowed on 'final' primitive types.

I agree with everything you wrote except that(!) I don't see a reason to accept 
compound assignment with a `final` variable.