statement unittest

[monkyyy]

I have this code:

```d
auto reduce(alias F,R)(R r)=>r.acc!F.last.front;
unittest{ assert(counter(10).reduce!((a,int b=0)=>a+b)==45);}

auto all(alias F,R)(R r)=>r.map!F.filter!(a=>!a).empty;
unittest{ assert([1,3,5,7,9].torange.all!(a=>a%2));}

auto any(alias F,R)(R r)=> ! r.filter!F.empty;
unittest{ assert([1,2,3,4,15].torange.any!(a=>a==15));}

auto count(R)(R r)=>r.reduce!((a,int b=0)=>b+1);
unittest{ assert(counter(10).filter!(a=>a%2).count==5);}
```

"unittest{ assert(..);}" should be reduceable to `unittest(...)`

i.e. `unittest(1==1)` would compile