[Issue 19092] __delete doesn't work with immutable

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=19092

--- Comment #2 from Radu Racariu <radu.racariu at gmail.com> ---
The problem here is not if `delete` or `__delete` are correct or not. The issue
is that the compiler deprecated `delete` and offers `__delete`as an alternative
(with destroy/free as optional) and it doesn't work as advertised!


This is a very bad in terms of the overall perceived quality, I don't wanna go
into the reasoning of why `__delete` was added (or kept), but we have it and it
should work with all language constructs!

As a side note, this is not the first time I report issues related to
const/immutable not being properly tested for druntime functions (__equals
caused a regression for immutable AA), I think making sure
cost/immutable/shared are covered for generic code should be a top priority
when reviewing code.

--