How Effectively Agents Write D

[Richard (Rikki) Andrew Cattermole]

 From my experience the number one thing LLM's trip over is actually 
out, they don't seem to understand its a keyword. But that's with 
DeepSeek/MiMo.

- -checkaction=context would be nice, but currently breaks builds

- Catch reads of NaN-initialised floats, implemented -preview=fastdfa

- Infer attributes for non-template functions, NOPE dmd isn't geared up 
to do attribute inference, this is a major architectural problem that 
isn't going to be fixed

- -preview=rvaluerefparam, has bugs, we want to turn that on in an edition

- un-reserve macro, ok yeah thats reasonable, we'll never have anything 
to use it at this point

- Let explicitly imported names take precedence over the implicit, 
maybe? But it smells a bit.