Walter Bright:
Apparently nobody writing an assembler ever had the obvious idea of tacking on a C front end so it could at least pull the struct declarations out of the .h files.
In D you can do the opposite: write the asm files, import them statically from D and parse and convert them with compile-time code into D struct defintions :-)
There may be issues with supporting an inline assembler and the GDC or LDC back end interfaces, that I don't know about.
I think GDC and LDC developers are willing to give you answers on this, if you ask.
Bye, bearophile
