Make `& Class.foo` illegal

[Avrina]

On Thursday, 27 August 2020 at 11:20:17 UTC, Johan wrote:
> Currently this code is not rejected by the compiler and instead 
> creates non-functioning (undefined) code:
> ```
> struct S {
>     void foo() {}
> }
>
> void main() {
>     auto a = &S.foo;
> }
> ```
>
> See https://issues.dlang.org/show_bug.cgi?id=21195 .
>
> Considering https://www.digitalmars.com/articles/b68.html, why 
> not simply reject `&S.foo` during semantic analysis?
>
> -Johan

This gets brought up often. The last issue was closed as invalid. 
This will likely never get fixed, the issue is that it is return 
a function type, when it should be a delegate type with a null 
"this" ptr.

"Just use @safe"

https://issues.dlang.org/show_bug.cgi?id=3720#c16