Optimizing away empty loop with step

[David Nadlinger]

On 30 Jul 2021, at 10:58, Vladimir Panteleev via digitalmars-d-ldc 
wrote:
> My second guess was that the C compilers were happy with optimizing it 
> away because signed integer overflow is undefined in C. But, changing 
> the type to unsigned didn't make a difference.

LLVM/Clang 10 didn't optimise it away for me with everything made 
unsigned. Clang trunk on Godbolt does, but that's because it makes use 
of the fact that infinite loops are UB in C (as encoded in the 
`mustprogress` function attribute).

  — David