[Issue 22174] New: destroy should be @nogc when class destructor is @nogc

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=22174

          Issue ID: 22174
           Summary: destroy should be @nogc when class destructor is @nogc
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: druntime
          Assignee: nobody at puremagic.com
          Reporter: sbuhesap at gmail.com

Pretty much same as the issue summary: destroy should be @nogc when class
destructor is @nogc.

A piece of code that should work but doesn't:

```D
import core.stdc.stdlib;
import core.lifetime;

class Example {
    int x;

    ~this() @nogc {}
}

void main() @nogc {
    enum size = __traits(classInstanceSize, Example);
    auto pointer = malloc(size)[0..size];
    scope(exit) free(pointer.ptr);

    Example ex = emplace!(Example)(pointer); // Error: `@nogc` function `D
main` cannot call non- at nogc function `object.destroy!(true, Example).destroy`
    destroy(ex);
}
```

There should be a @nogc overload for destroy that allows people to use class
destructors. Currently there is no way to call destroy in a @nogc function
without breaking the type system. 

Or just un-deprecating class allocators / dealloctors would work too.

A recent discussion I found about this:
https://forum.dlang.org/thread/jsrjgmeblfukwhqbwjab@forum.dlang.org

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