Can you shrink it further?

[Stefan Koch via Digitalmars-d]

On Sunday, 9 October 2016 at 22:11:50 UTC, Andrei Alexandrescu 
wrote:
> Had a bit of a good time with popFront for UTF, got to this: 
> https://github.com/dlang/phobos/pull/4848. I suspect there are 
> cleverer things that can be done. Can anyone make it tighter? 
> Take a look at the disassembly referred to in the pull request. 
> Thanks! -- Andrei

With -Oz both functions look almost the same on ldc and gdc