[Bug c++/104981] [coroutines] Internal compiler error when promise object's constructor takes a base class of the object parameter

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104981

--- Comment #5 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Arsen Arsenović from comment #4)
> the latter seems OK to me - mind proposing a patch?

I am planning on doing some rework on the ramp code-gen in the (very) near
future - so can pick this up on the way (unless Patrick has already done it ...
)