Improving assert-printing in DMD

[Per Nordlöw via Digitalmars-d]

On Thursday, 1 October 2015 at 14:37:55 UTC, Andrei Alexandrescu 
wrote:
> Whoever wants to work on better assert expression printing: 
> make sure you specify which grammar constructs are supported, 
> and how the parts involved are printed. Expressing semantics 
> via lowering would be great. Write a DIP, discuss, implement. 
> I'll have your six.

I registered a user named `nordlow` at the D Wiki but I can't 
find a way to write a DIP.

Help please.