DasBetterC: Converting make.c to D

[Kagamin]

What I had with actually modern C:
1) narrowing conversions
2) not only arrays decay to pointers, C happily allows the 
opposite too, eww
3) looks like C code loves to have function arguments named `in` 
and `out`

Also difficulties with transpiling to C don't look that big: 
errno is the first glaring example TLS usage in C, glibc even 
tunes TLS model for it; AFAIK, C++ stores current exception in 
some sort of static storage and provides a function to retrieve 
it from there, a similar approach can be used for C target, 
though betterc shouldn't use exceptions.