ImportC and #include files

[jmh530]

On Monday, 8 May 2023 at 20:12:44 UTC, Walter Bright wrote:
> Support for C macros being accessible to D code is very 
> limited, pretty much just enums for constants.
>
> I plan to improve this in the future, but it's what it is today.

Cool.

What I was reporting above was mostly due to these missing 
builtins. I think some of the simple ones with #if were working 
otherwise.