[DDMD] Issue 13161 - Wrong offset of extern(C++) class member

https://issues.dlang.org/show_bug.cgi?id=13161
> Walter, your compatibility things don't work.

They do in this case, and I wouldn't write them if they didn't work. They make testing a lot easier.

> We break abi compatibility all the time.

Not without good reason.

> You are wasting your time and adding cruft to the source.

We've done this many times in the past. It saves time.

>  It will also reduce memory consumption in some cases, as you can see from the modified test of classinfo size.

That indeed is a good reason. You should have mentioned that first :-)