Inconsistency between `AllMembers` and `hasMember`

[Adam D. Ruppe]

On Saturday, 17 November 2018 at 20:54:24 UTC, drug wrote:
> https://run.dlang.io/is/IygU5D
>
> AllMembers states that struct S contains "this" member, but 
> hasMember negates it. Is it bug or misusing?

I'm not sure what it is supposed to do, but since this is kinda 
special - it is a keyword for the constructor - I wouldn't expect 
it to be accessible this way in any reliable manner...