The non allocating D subset

[Adam D. Ruppe]

So I tried to get moduleinfo looping working.... and found some 
success. If you use it with libc, it works. On bare metal, it 
works thanks to a linker script hack. It doesn't work on the 
minimal linux setup. I wasted a lot of hours trying to do it, but 
there seems to be some elf section magic going on that I can't 
figure out how to easily hook in to.

But even with that working, I couldn't get module ctors working 
right.

Meh time to move on. Here's the list of stuff I'm abandoning so 
far

  What doesn't work:
     1) array concats. use the module memory.d instead (link 
failure)
     2) module constructors and destructors (silent failure, they 
never run)
     3) looping ModuleInfo without libc or bare metal (silent 
failure, returns empty list)
     4) TLS variables. always use __gshared (runtime crash)
     5) threads.
     6) unittests (silent failure, they never run)

Maybe I can figure out module constructors later, but for now I'm 
just going to abandon that.