[Bug d/117621] [13/14/15 regression] runnable/mangle.d test fails with -g (d21: error: type variant differs by TYPE_PACKED)

[ibuclaw at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117621

--- Comment #2 from Iain Buclaw <ibuclaw at gcc dot gnu.org> ---
Reduced test:
```
void test8847e()
{
    auto foo()(inout int)
    {
        struct Bar {}
        return inout(Bar)();
    }
    auto bar = foo(0);
}