[Issue 19563] extern(C++) Incorrect ABI passing small struct

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=19563

--- Comment #2 from Manu <turkeyman at gmail.com> ---
If anyone knows how to fix this; here's a head-start:

  https://github.com/dlang/dmd/pull/9411

That commits the unit-test which needs to work.

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