#dbugfix Issue 16189

[Kirr]

https://issues.dlang.org/show_bug.cgi?id=16189

This is a P1 critical DMD bug, silently generating wrong code. 
Reported one and a half year ago, but exists in DMD compilers 
going back to DMD 2.050 (possibly more, but this is as far back 
as I tried).

The repro is essentially C, it involves nothing but array, struct 
and loop. No templates, CTFE, no phobos, no any fancy features.

I can fully understand that may be this bug is hard to fix, that 
there's not enough manpower, that there are other more pressing 
issues, that no one can be expected to work on something they are 
not interested in, etc. And may I'm the only one affected? (it's 
a mystery to me). But this bug is a phychological obstacle to my 
use of D (or rather DMD, because LDC seems OK). May be it's just 
my expectation that is too high.

I'm not ready to give up arrays, structs or loops. I 
experimentally worked around this once I found it, by re-wording 
the loop. But I've no idea how to make sure this bug won't hit me 
somewhere else. I guess I can live without optimizer (or without 
DMD). In any case, I think that miscompiling a simplest C-like 
loop does not send the right message to a newcomer.

I'll appreciate any help with this bug.